I believe that would enforce the nationalism, players from the defeated realm would hold their honour and die with their nation. It makes sense to me, that would fit perfectly with the rule that once you are in a realm you can not switch from it.
I'm not sure how you got that out of Zakky's post. The difference being people can still play with one, while in the other they can't do anything until one of the other countries falls, which can take months. Not exactly fun.
