Team limits should be added to classes of Zombies like Zombine and Fast Zombie.
FOR EXAMPLE
Zombine - 2/2
Fast Zombie - 3/3
If they aren't locked to a team limit, the entire Sewers would be just filled with Zombine or Fast Zombies, lacking variety and making it unfair for other players.
Another talking point would be the Grenade that Zombine have.
Either it doesn't do enough damage, they don't have it or only a 50% chance to spawn with one. I'm not a balancing god but I'm throwing some suggestions here so it isn't painfully annoying to face our loveable rotting corpses.