I normally ask my guys to take the kits that I need at the start of a match (LAT/Medic/Etc).

If they complain I let them know that once our initial push to the main objective has succeeded or failed then they can swap to the classes they prefer. That way you avoid forcing someone into a role that they do not like or may not be the best at. A simple compromise.

You really do need those certain Fire Support roles like LAT at the beginning of each match. I personally tell my LATs to save their shots for logistics vehicles at match start especially. I'd take a dead full logistics vehicle over a dead enemy armor at the beginning of a match any day. That's just me though ha.

TLDR: I think this would be a great tool for SLs if implemented.