The current system as it stands is complete nonsense. Games should never start with lopsided player counts, and it’s ridiculous that this has been allowed to stay the way it has for this long.
When players first load into a game, while people are still being brought in to fill the teams there should just be a little warm up mode, a quick TDM or whatever for players to play until both teams are full, at which point the actual match would start. It makes no sense whatsoever for the game to just go “oh well, looks like we’re out of time. 8 vs 5? Seems fine to me!”