While I do think they are too common, I think its because my view was that most of the zombies had serious injuries that were implied. So while there are crawling zombies, they are mostly rare and could be the product of reanimation of dead zeds with serious injuries.
I don’t know how the game works, but is it possible to have it where corpses that are decapitated raise without their head? The feeling I get from the Goo is that it is a parasite that mostly controls the spinal cord, and thus nervous system, that doesn’t technically need the head. Given that we have skeletons and scorched zeds, those realistically would not usable tissue (napalm, especially, tends to destroy muscles), so the goo is presumably doing a lot of work then to replace and repair tissue to retain mobility.
So I think they are fine, and make sense, they just spawn too often. It might also open a rabbit-hole of “what about x zombies” but as far as I understand the lore, its fine. I am not sure of how useless they should be, they could have immunity to headshots, (which i don’t know if they have already) and be able to be herded by necromancers/masters.