To be fair, you don't really know much about the warden in dao. You and Alistair are really the only wardens and neither of you know the horrors that the wardens have performed before.
Reading the last flight gives you more insight into the lengths they go through and how nothing is really off limits for them.
Wasn't there that DLC Wardens keep? Where you met that demon and 'Avernus'? And showed you what was happening during the fight? Summoning demons and such blood magic and all sorts. It seems every time the wardens get driven into a corner they use blood magic.
Still i did save them a few times but then i noticed that thing 'The Grey Wardens can still be influenced by Corypheus' if you let them stay. And i don't know really the choice itself doesn't seem to affect the story much besides approval. I can't recall seeing them in the end battle either.
And since i've played through DAI 3 times already i've not noticed any difference in the end.
-Siding with Templars kept wardens, still tons of Red Templars, hardly see any mages and haven't seen 1 warden.
-Siding with Mages and exiled the wardens, still tons of Red Templars, hardly see any mages (Which would make sense).
-Siding with Templars and keeping Grey Wardens, haven't seen 1 warden fight..
Keeping the wardens (never seen them again)- Hawke dead/alive s/he is gone also can't recall seeing him/her in Skyhold after the fade when alive, the only reason to keep Hawke alive is to keep Varric happy, and tbh i kinda did like playing as Hawke.
Exiled wardens Hawke going to 'guide' them to Weishaupt?? WHY????
What i don't get is this, why is there no option that says 'Go to Weishaupt until this is over for your own safety' instead of banishing them, and as others mentioned they saved the 'world' from 5 blights.. That should give em something.
The only difference between siding with the mages/templars i've seen is that you either run into Samson or Calpernia in the end..