Challenger 2 and challenger 2 TES pack Low-poly 3D model is available on CGTrader for $120. Original author: kollegaboss25. Specs: 26061 polys, 21007 verts.
OBJ (OBJ, filesize: 165 MB), MAX (Autodesk 3ds Max, filesize: 165 MB), FBX (Autodesk FBX, filesize: 165 MB)