I am ... not in favour. I don't think it's a bad idea, I just think that there's a lot of hidden officer work here in determining which teams will be placed by which person.
You'd have to find a way to dramatically cut the Officers' work somehow to make this work with the schedules we already keep.
On top of this concern, however, I don't see how placing units rather than squads or fleets would work. Who gets to play out the battle in that case?
It would still be too much work, but a better idea is 1 defensive squad, 1 offensive squad and 1 "reserve" squad. If your guild doesn't place enough squads on defense, then the blanks are filled with reserve squads, using up the highest GP squads first until all defensive positions are full. On offence, you have to use an offensive squad on your first attack against an enemy defensive squad, but for subsequent attacks, you pull from your reserves.
I mean, there's the core of something that could be very interesting here, but I just don't see how it works with donating 1 unit at a time, and with donating 1 squad at a time, I don't see how it's sufficiently different from TWs.
If this replaced TWs, okay, but added to a busy schedule? Meh. Not in favour. We just have enough going on in the game and people have real life to deal with.