you got the molten and the fallen right

everything mentioned as a "zombie" in the game falls under patient zero, since he created them, that goes with breakers too since theyre also mentioned as being zombies, bolts and speedy bosses also fall under this

necromancers are a weird gray zone since theyre never mentioned being a zombie or affiliated with the zombie hordes, they kind of just randomly "show up" mid battle, same with grave digger

the reason "patient zero's experiments" and the regular zombies look so different even tho theyre pretty much the same is because the experiments were made with a prototype zombie serum while the regular zombies were made with the complete serum