it techinically does not but it does
.
EX: bunker
a marine in 1x1, once you put it in it becomes 2x3(or 3x2).
same with transports...
i dunno what this can be used for, but its usefull if you need to fit 4 units into a single 1x1 square
funny, i was playing civilization on SC and when i upgraded my archers to rifles(ghost) it remove 3 out of 4 units in my bunker, leaving only one outside it...why? i dont think the creator used remove all....
so maby it messes up the remove 1, and removes all of them instead!
i hope this will help unless it's already been found out.