[MaxWilson]

As I recall, if you Teleport a SC on top of a besieging army he will wind up inside the fort and you'll have to order him to Break Siege the next round. I find this annoying, so I typically have someone fly in instead w/ Winged Boots, resulting in an immediate attack. I expect Cloud Trapeze to work the same way.

I.e. in your situation, they wind up inside the fort helping the defenders.

-Max