Possible Siege defending exploit? Or just a sneaky trick?

[PBI]

Interesting trick. Generally it is quite easy to stop rams via an exploit if you send any unit out to engage the unit pushing the ram; the AI will almost never pick up the ram again and carry on. This exploit seems even better though; if you push a pair of catapults through the gate, and dump them such that there's no room for a ram to pass on either side, I can't see what even a human player could do about it since only another catapult crew would be able to move them. The AI would be completely sunk since I've never seen it attempt to attack another gate, but I suppose a human player would; however, nothing to stop the defender from sending the catapult crew out to pick them up, march them through the inside of the city, and dump them again outside the other gate.

I suppose you could send a sacrificial unit to park on the catapults and kill the crew if they come near; still a huge inconvenience to move the entire army 90 degrees around the city plus almost certainly lose the unit guarding the catapults. I imagine I would be fuming if someone did this against me.

Oh, and ramming walls is only possible against towns and motte & bailey castles, which barely offer much in the way of defense anyway.