He also did The Crazies which had infected (zombies) people his partnership with John A. Russo split when he didn't like the faster Zombies of the genre.Watch George Romero's zombies and also the Walking Dead. They are undead, not infected people that feel pain and are smart. Since when does a zombie punches you? Since when zombies know how to avoid traps? It's totally bull...sh.it... They should be stupid as hell and with no special abilities.
Z Nation has many variety of Zombie and continued the development Romeo started in his Land of the dead.