Given the way that units are custom designed, this could very, very easily be exploited if not implemented carefully. For example, it is simply impossible to allow unit upgrades in the field since it means you could simply deploy a bunch of really wimpy units quickly right at the enemy and then upgrade them to fit whatever role is needed on the battlefield.
Frogboy, will regular troops be able to gain experience in the release? Otherwise it seems the player might as well use champions rather than regular trained troops.
I haven't gotten very far into the game yet, but really, c'mon. Who do you think is going to win: a few champions or a few champions each with an army at their disposal?
Anyway, because of champions, I'm not sure if it's necessary to have regular units gain experience.