I cant quite remember now but I think it was 2 different sets for body, arms, legs and torso and then only the face textures being unique. Then just using colours and variables to make them seems different.
The challenge was that I only had a nvidia RTX 2060 with 8GB of vram. And well that is quickly an issue when doing a lot of models

my newest work for instance could not fit on 8GB of vram and you would need at least 12GB to do it in a single render pass (I do very little to no post work on a lot of my stuff).