Doesn't matter you still talked past what I was saying, but at least in this response you're actually addressing my point:
The orphanage and the enemy variety are gameplay critiques, not visuals. The enemy variety in something like RE4R is far more diverse in their sizes, how they attack, their weaknesses and their behaviors. This leads to differences in how a player approaches fighting them and with what weapons. Enemy variety has a visual factor, but it mainly affects gameplay.
The Zombies in RE9 may wield different weapons against Leon, but the vast majority of them all have the same weaknesses and behaviors. It's just enough to feel truly diverse. We could've had Cerberus, Evolved Hunters, Brain Suckers, and a whole bunch of other enemies that would offer way bigger difference between enemy types.