Unless a builder worked for both games, most likely they both used a similar reference image. The flat shaded “low-poly” style is common in these types of games, so it might just be a coincidence.
Here are the links to the assets they are most likely using:
It could also be that a same builder made those and just sold their assets to those games, look for any links in between those places and their creators maybe you’ll find who built or uploaded them originally.
Yeah, these 3D models can be purchased from CGTrader or Unity Asset Market. Recently, some games, such as a few of my own, have been utilizing low-poly 3D model packs. It’s significantly cheaper than hiring a builder and saves you a load of time. Just make sure you’re buying a pack that uses an atlas texture because this allows you to import a massive volume of meshes without having to upload and match an excessive amount of textures. The atlas texture can be applied to all or at least a large category of the assets. This is only possible with low-poly packs, since a more complex mesh would require its own independent texture. That’s just my two cents.