Okay I just had an idea, tell me what you think of it:
This last game of warzone we had 5 quitters. That is obviously nigh impossible to come back from, but what makes it more impossible is that when you start getting dominated from greater numbers like that, you very quickly fall behind in REQ level so then you have to fight all these advanced vehicles. So I propose that when you lose teammates, your whole team goes up REQ levels. 5 quitters? 5 REQ levels for everyone. Now, this certainly doesn't mean your whole team will have the cards to spend or want to, but it at least gives you the option of possibly fighting tank vs tank to do something other than wake up, walk outside with your measly small arms, and die almost instantly again and again and again for like 10 minutes or however long it takes to finish the game.
OR
Just give us the option to concede loss after 4 people quit.