Some people on this forum mentioned that it is basically pointless to choose a faction since you can play as any hero. They are basically right.
Well, I do not really care about the faction war. It doesn't matter who wins, at least for me.

But here are my suggestions anyway:
1. If you play as a hero from your faction you will get bonus assets to place on the war map. You can still play as heroes from other factions but you will receive less assets.

or a more radical solution

2. If you play as a hero from another faction you receive no assets at all.

3. (apart from the faction war stuff)
There are always two sides in Dominion. Attackers and defenders. Each side represents a faction (viking, knight, samurai minions). How about we have to choose one of the heroes of the represented faction?
For example:
If you are on the Defenders Team and you have Knight minions on your side, you have to play as a Knight hero. If you have Viking minions on your side, you have to play a Viking hero.


Please tell me your thoughts on this.