This is a paid asset, but now you can download Animated Soldier (ver2.0)- Lowpoly Free.
Detail this asset from Unity Store: Original Link
Animated Soldier – Lowpoly v2.0 (Latest version)
“If possible, please buy the package to support the developer”
Animated Soldier ver2.0- Lowpoly
Soldier : 1024 diffuse, 2112 triangles
Gun(RussianPistol) : 512 diffuse, 387 triangles