Staging area creator ability to dispatch units that are from another user

I mean in the way that when another user sends their people to a staging area made by another user, the user that created the staging area to have the ability to dispatch the units that aren't theirs (because the person sending over units voluntarily sent their units for mutual aid) and then give the ability to the original unit owner to stop the response of a unit if they would like (to even out the power between the staging area creator and units' owner).