I think this is a neat idea because I'm crazy and I like anything that shakes things up and makes them different/constantly changing. Imagine the increase in unpredictability if players might not have access to their favourite drop deck or 1 mech on that deck because it was in the shop being repaired (mandatory wait period based on level of damage sustained). It might make the higher level matches a bit more unpredictable, and even give pugs a chance against real teams (or at least we might get stomped a bit less) if those teams just came off a bad loss and are now playing backup mechs.
I agree that its probably not feasible in reality but in theory I think this could be fun Greyhart. Maybe in my imagination I'll add in the salvage stuff from Mechwarrior 4 so that you can actually lose a piece of gear from your mech and someone on the other team can actually claim it LOL...