Question about making uv unwrapping models for game engines

Hey, I’m working on my first serious game. When making a model, it has multiple parts. It has a bunch of teeth, a rocket launcher on its side, and a gattling gun, and a bunch of tentacles on its head.

Ok so heres my issue…Ive never made a serious model like this before. I would like to make textures for it. Take the teeth for example, it has like 20 teeth and when importing into Unreal will I have to add all the 20 uv maps by hand to each tooth material? Should I make the teeth one piece? Should I just combine the whole mesh and uv unwrap it like that? How are complicated models usually uv unwrapped for game engines? As all one piece or a bunch of separate pieces?

pic of the mode is attached.