Since currently total kills is what puts you in 1st, 2nd, 3rd and so on. This kinda generates a somewhat competitive environment for survivors, fighting to get the most kills. Which is odd because it’s a team based game.
Instead of having to worry about kill stealing. Make the payout and score based on damage done to infected, instead of whoever got the killing blow.
(A change like this would also be nice for Zombie Massacre.)