I have meant transfer (castle A -> castle B -> looting/fighting army A+B), not support... well, thats nonsense for me... but ok. I knew about possibility of relocate my paladin.
Yes, your army can be sent as support, usefull if you need a safe place for it or if you are supporting a tribe mate. But it cannot be moved to a different villa to send attacks from, you have to recruit troops in each villa to do this.