It's a very good idea, no one forces you to change your armies, but sometimes due to low availability of certain troops, I really have to. it doesn't destroy anything for you and for those interested is desirable, so no biggie.
changing runes with each other doesn't destroy anything? :D. one might argue it does and he would be right. but you always have to choose, so it' all about flexibility.

there is no resentment, but I'm sick and tired of waiting for english versions of various games (disciples 3 is another remarkable example, not to mention many german adventure games), so....