Neutral Units

I've been thinking but when people lose/surrender/leave, their units become neutral. How about if there are units outside the cities, whoever gets to them first can salvage them as extra troops? Especially non-land units like air transports and sea transports, so that land units who attack them can have free rides. Maintenance will go to the troop expenses, but you don't "buy" them. Another thing... to commandeer them, you obviously need to overpower them, so for example, 1 tank against 5 air transports won't let the tank take it. 4 tanks against 1 air transport will allow them to have a free ride next turn with half air trans movement, and once they get off, the tanks can move their own original range (5-10 depending on strategy).

As for attacking land units, I have no idea what we can do with, but for other offensive units like neutral bombers or destroyers, if the attacking troops can take it, they will destroy half the neutral units and commandeer the intact half. For sentries, they will be stealth, but be a downgraded version, maybe half everything (except attack... keep attack at 1).