that was already like that. going around with enough siege engines to be effective in a siege was a pain, it really made an army less effective. It's indeed a different kind of "it will be difficult to carry them around when there is no siege" but it's still an already present effect.
It just slows you down. They have no maintenance costs at the moment. If they cost 5 gold a week each, I'd be much more careful about how many I carry.
