I'd say Ioverth's path in creating a whole new multi-racial kingdom in the north is just as equal as saving the Temerian throne with Roche's path saving Anais, if not better (considering a possible Nilfgaardian invasion will happen really soon and Anais is not that capable in both mind and age to govern through that).
Anais is irrelevant. Giving her to Radovid however is as sure as hell not.
I want to see how this so called kingdom of yours will work. You think you just snap your fingers, make some laws and bam you have a multi-racial kingdom. then well frankly you know zero of politics or history.
You bring up and interesting point that the other kingdoms won't support Saskia's kingdom (let's call it the Pontar for simplicity in this conversation) in war. Well that's not the case. Last I recall, Pontar is not at the border of Nilfgaard, that's Lyria and Temeria (if I'm reading the map coorectly). So if Nilfgaard were to invade then the Northern Kingdoms would have to band together, just like they did at Sodden and Brenna.
Lyria and Aedirn are going to fall easily, just like they did last time around, this time even quicker since Lyria was weakened by the old war and Aedirn has no monarch.
The Imperials once reached the Pontar valley, where they only stopped because of a deal with Henselt, they can do so again, and even go beyond this time. Henselt might just launch his second invasion anyway, and if he brings a strong army, not just 2.000 if even less troops, then you can bet Saskia won't stand a chance....
The pro to the newly-formed Pontar is that the North now have the best archers in the known world, the Scoia'tael, not to mention any assets the dwarves can make. With Pontar the terrorist acts of Scoia'tael would be gone, sure there might be possible rogue bands, but not to the degree of full on guerilla war of the past.
England had the best archers in the Medieval world, and they still lost quite a few wars. The real reason it was never conquered it was because of it's Island nation status with no strong foes on the Island...as for the dwarves? What can do they do that is special?
You think 1.000 men is an army? Laughable, that's not an army and furthermore it's not organized. You think they would stand any chance in a pitched battle and not a castle assault?
That battle wasn't won because of Saskia's leadership skill, it was won because Roche had weakened the Kaedweni army with his plot and because Geralt, the badass, was there....why do you think Vergen falls when you fight on Henselt's side?
And to futher strengthen this foresight, Saskia must be pretty stupid if she doesn't aid the rest of the North against a Nilfgaard invasion. And judging from what we learend from Saskia, she's anything but that.
She is pretty stupid if she thinks racial tension can just be melted away just like that.
How exactly is she going to create an army? From what money ....having the richest province in the north doesn't mean anything if you don't have trade, and who is going to trade with her? Kaedwen? Redania ( Radovid would likely have invaded to bring Saskia down from her self proclaimed throne if not for him wanting to split Temeria in two with Henselt )? Aedirn...
She has no economy, no skill for running one, nor does she have the skill for the logistics related to running you army. What you are trying to say is that somehow Saskia's nation would survive because the north would need her help, what I am saying is that ( based on historical evidence ) every single medieval monarch would sooner have cut off his own hand before accepting a peasant on a throne.