What happens if an army's home region becomes part of another realm? Say, if a duchy seceded and took an army's home region with it, does the army change home region to the capital, does the army go to the new realm, or does it just get disbanded? And would it make a difference if the army sponsor also went to the new realm during the secession?
I believe the army transfers to the new realm if the sponsor goes with it. Otherwise I think it disbands. I'm not 100% sure, though.
sort of encourages armies to be really centralised, doesn't it?