Ah, okay. Then yes, I wholeheartedly agree with your comparison with Assassins Creed.
It is very similar AI wise, and it does get frustrating at times when you're surrounded.
Funny enough, I don't think it's a AI issue at times with this game.
Spiderman didn't have the best AI either, but I believe it's the mechanics in that game that allow you to work through a dozen enemies efficiently.
I think that's somewhat missing in GoT, but I'm led to believe the weapon wheel UI is just a nightmare to work with mid combat - because it gets confusing when you're knee deep with enemies.
Alas, all these things you and I can only hope improves in the next generation and in the sequel.