TECHNICAL REQUIREMENTS MODEL WORK WITH CGTRADER

i would say that you should bake texture maps for details and make big shapes with polygons

if you use blender . so you can use un- subdivide .

Show us wireframe, it will be hard to tell it is posible or not.

You need to clean your mesh, removing polygons where they are not necessary.
I'm not an expert, but that's what I've been taught;)
An image might be more understandable :)
https://i.postimg.cc/NjP63Zmh/Sans-titre.png

Hoping it will help you.