OK, after reading this thread, i can see:
the whole world is different ;D
Messiah's solution is absolutely correct.
Transport Unload - let's a vehicle get rid off all of it's cargo
(mounted troops). If there are 3 different groups mounted
on a vehicle, all will get unloaded with using a transport unload
waypoint. There's no need for GetOut waypoints or for
unassign vehicle commands. The game engine does that
for itself here.
Unload - this waypoint works in combination with a GetOut
waypoint. If there are 2 groups mounted on a vehicle, and
you place an unload waypoint for that vehicle and a getout
waypoint for one of those 2 groups (syncronize the 2 wp's)
The group with that getout waypoint will be unloaded, while
the other group will still remain in that vehicle.
No unassign vehicle command is required here.
EJECT units by action commands from e.g: a chopper,
does require an unassign vehicle command
:edit
btw - there's no difference between units/groups mounted
by scripting commands (moveincargo), or mounted by
GetIn waypoints.
~S~ CD