I was always more fond of the idea that when it goes down to 1 model it is unable to fire and has to be reinforced.
I actually like this idea a lot. I doubt we'd actually be able to get a squad size change, but that kind of mechanical change is a lot more likely. The only thing is, the reinforce cost would need to be pretty high (200mp+), since you're basically getting a 2nd chance to save sniper vet.