"Potential" is too ambiguous a term. If you are just talking 'potential', then all the origins save for the Dwarven Noble (who would surpass them all in skills, and experience) would rank exactly the same, because all eventually do survive the Joining and become awesome wardens. Because you haven't assigned a criteria being to their 'potential', just an ambiguous term (skills) that only you seem to know what you're looking for in a candidate, it's hard to rank them in terms of their potential because of this. Skills come in all kinds of categories.
Duncan was all the way in Highever because of 'rumors of skill' to recruit the Human Noble, and the fact that the young warden recruit has leadership skills (something Duncan makes note of in your first conversation with him) in addition to the best formal training money can buy would put him quite a few notches higher than the 'mother trained' city elf--who isn't even allowed to carry weapons or armor, so where do they even practice and keep said skills sharp? Even if they had been able to hide (potentially a honking huge 2 hander or bow) for practice, he has no inkling of what kind of person they might be, will they get along with their fellow grey wardens, do they hate humans...etc. Just because he knew their mother (and her only criteria seems to be she was a 'fiery woman' and could handle blades), that doesn't mean her child has the same level of skill--and actually because she lacked diplomacy (the reason she's dead), it would rank against recruitment. Why recruit someone who potentially could be a trouble maker or won't get along with his fellow wardens when so many other good candidates could be picked out so much closer to Ostagar?
Diplomacy/leadership skills--is quite a valuable asset, not only at the landsmeet, but among your fellow grey wardens AND the nobles in the land, or in any human situation for that matter--and becomes vitally important in Awakenings, because the Warden Commander's leadership is what's being tested in that expansion. Duncan is no fool, the grey wardens are not a large or popular group in Ferelden, having only just returned thanks to Maric two decades prior. He will say as such if you poo-poo Cailan as a silly man telling you that you shouldn't speak that way since Cailan 'is one of their few allies'. After the Blight is dealt with, there is the mission to build the order, restore order to the nation and the people will look to the grey wardens to do that if there are darkspawn to continue to deal with. And Duncan is aware of this as well when recruiting.
Everyone is different, different people assign value to a lot of different 'potentials'. We had quite the discussion upthread about how much value Duncan (who was all about 'killing darkspawn') would place on someone who actually killed darkspawn vs someone with no practical experience with the enemy he will be fighting. You think it's not a consideration (aside from the truckload of darkspawn the dwarven noble kills) and feel the city elf (who has only the training mom gave him/her) ranked a lot higher than I felt they deserved, simply because he racks a bodycount in Vaughan's estate--something Duncan couldn't have predicted when he came to Denerim. You have already pointed out the Human Noble kills even more than the city elf, and Howe's men were warriors/rogues, there to lay siege to the castle, not complacent rapists/guards being knocked off in their leisure time. Perhaps you should list the criteria you feel are the most useful to the discussion, instead of arguing the merits of this or that value, because people are going to weigh in with a lot of different ideas as to what makes a 'great potential candidate' vs a lesser one. And they may not agree with your assessments either, but that doesn't mean they are ignoring 'potential' they just see potential where you don't.
Because breaking up quote blocks is annoying, I'll just go paragraph by paragraph. Easier that way. A paragraph of mine will be responding to your own paragraph, like my first one is to your first one.
It's not ambiguous. Like I said from the start, who is most actually worthy of being a warden. Imagine it's a competition, with the winner being the most skilled fighter who has accomplished the most to prove they would be the best recruit. It's not that complicated.
Yes, human noble is pretty damn good. Yet they need lots of help with their mabari and mother and castle guards to go through 48 soldiers, while the city elf only needs her cousin who has never used a weapon in his life to kill 27 soldiers plus 3 mabari. Lesser number of soldiers, but the Cousland has EXTREMELY better help than the city elf. Regardless of the crappier training, they still outperformed the Cousland there. The city elf just flat out shows a more impressive feat of killing ability, regardless of the tales of the Cousland's skill. Now granted you could argue that the Cousland could have also pulled off the city elf's scenario... But who knows for sure. Facts are facts, and the facts are that the city elf showed better fighting capability based on what
did happen. And the point about not knowing what they're like? Wrong. The elder who is friends with Duncan has told him about the city elf before, Duncan alludes to knowing QUITE A BIT about you in conversations with him. So he already had a very good idea what to expect from you before he arrived. And by the way, you put a point in the Cousland's favor for going all the the to Highever just for them? Well Duncan went all the way to Denerim just for the city elf too.
Grey wardens are supposed to be neutral and not get into politics. Ergo, political ability is not even considered in grey warden recruitment. You must remember that needing to get political and there even BEING a landsmeet was something that was never supposed to happen to begin with. You're off to recruit someone and your order is meant to remain neutral at all times, are you going to
factor in political ability considering that? You shouldn't. The only reason you had to was because a ton of factors happened that shouldn't have necessitated it, you shouldn't plan for something that should be impossible. One may as well try to plan for the moon crashing into the planet. And the "rebuild the order" thing? Irrelevant, they would have sent a senor warden to do that... Which they DO if your character dies. You only become warden commander because of those very same factors they made you need to get political when you're not supposed to, but the plan would was never to consider
your recently recruited ass to be touching anything close to a leadership role.
(this part needs a few extra paragraphs, consider everything below to be my response to the final paragraph)
Why do you assume the guards were complacent? Because they're bad people? Right, being morally bad definitely means they have less training and skill (sarcasm)

than HOWE'S MEN. You know, because Howe's men are so much more morally superior?
"But I swear the arl's men are more criminal than the miscreants we occasionally arrest. Some of them
are the criminals we have to arrest"
Oh right, never mind then.
Again, there's a difference between taking a few disorganized darkspawn in a ruin that are being hit from 2 different sides and being in the actual deeproads where entire bands of organized darkspawn roam. That's why I count it in the DN's favor and not the DE's favor. Dalish handles about 7 darkspawn with significant help, with Duncan hitting their back ranks, on the surface. That's not the same as leading successful campaigns against entire companies of darkspawn on their own turf.
And yes, best case scenario Duncan would have recruited you without you needing to do anything to prove yourself. Yes it's merely bad luck that each Origin has the person needing to kill dozens of people. But some go through worse scenarios than others and who's backstory shows more impressive skill and experience. My criteria is very simple and I can't understand how people think it isn't. Look at each origin scenario and the backstory of each character and the number and type of enemies they go through and the kind of backup they had while fighting said enemies and tell me who looks like they'll be best at killing lots of enemies and possibly leading others against enemies if it is required, that is how you should be scoring.
Fyi, about my scoring, I consider the average soldier to be a 3 as far as worth for being a grey warden is concerned. Which means that Ser Jory for example, along with most everyone at Ostagar, is a mere 3 too. So I'm still giving good accolades to the Dalish, they're still being just under TWICE as worthy as the average well trained soldier in the King's army. With the Casteless being 3 times better and the dwarven noble being a little more than 3 times better. Maybe this will give perspective to my grading?
This is what I admire the most every time I compare all six characters; the fact that by the time Duncan found the Dalish recruit, they *were* sick, they *were* dying, and yet they had the strength to live - and even fight when it was needed - long after they arrived at Ostagar and, on top of that, survive the Joining. I always thought that was badass. The Dwarven Noble also survives against all odds (facing the deep roads with nothing but a measly sword), but they're healthy and they've been fighting darkspawn their whole life.
Then again, Dalish is one of my favourite origins - in case my avatar doesn't make it abundantly clear
- so I'm not the most objective one to talk.
That's more because of the Keeper's magic than their own resistance. Not to diminish them entirely, they obviously have a good innate resistance to the blight to have even lasted long enough for her to start using her Keeper-mojo on them in the first place.
If I took anything from this discussion, it's this: I ranked the Dalish far too low (probably because I just find the origin boring).
Duncan would reason that a living adequate warden would be far more valuable an asset than a dead potentially awesome one .
Ultimately, surviving to actually be of use to the wardens makes a recruit far more valuable than any 'skills' since skills can be taught. Survival of the taint seems to be a crap shoot that can't be predicted. In this, the Dalish's "accomplishment" outranks even the Dwarven Noble, who has a lot more skill/experience but lacks that one factor.
That factor is what made me bump them from a 4 to a 5, so I did get swayed to a point about them. But I can't see going through a ruin with some skeletons and taking on 7 darkspawn in 2 separate battles with a mages help to be equal to carving your way through a Carta base after winning a proving without training, or cutting through a small army invading your home, or killing an entire arl estate almost by yourself, or being a mage, or (insert a million impressive things about the dwarven noble here).