Nilfgaard's version of this is clearly whitewashed if you compare it with the one in TW2 and the books. Apart from the respect to the non humans, Nilfgaard wouldn't had done any of this.
Most of the nations in the empire are vassal states, so Temeria's fate isn't too unbelievable, Emhyr also needs to end the war quickly as he has plotters about to go for his back...
As for putting Dijkstra in a place of power, that sounds super dodgy to me... Spymaster turned ruler.
There really isn't any real winning when it comes to the political side of TW3 your choices are;
-A foreign Emperor who's after your daughter so he can not get himself stabbed.. who will restore my beloved Temeria but strike down the rest of the North
-A Spymaster who has no trustworthy features in his personality and will never lose track of where Geralt is - making his plans of running hard - and making the north a little less stable but victorious in the short term
-Or a great leader - who doubles up as the man who is likely to kill you and everyone you love in the world, but save the North utterly while he's at it..
I'm selfish :x ~ As long as Yen, Triss, Ciri and myself can go away at the end its all okay.