If you are looking for decent 3D models of current/modern vehicles of the US, Russia, and China, checkout my Thingiverse page
https://www.thingiverse.com/cpangracs/designs. Most are sized at 1:216 scale, but can be resized to 1:285 for some games, and larger for others. These are best printed on a resin printer. I add new models as I design them per requests from active duty servicemembers around the world. They are designed solely for 3D printing.
Happy gaming!
Curt