- There is nothing "not correct" about the areas you outlined in red in the Cyberpunk weapons and the other professional model. - Regardless of a model coming from CAD or being manually crafted and/or retopo-ed (or anything inbetween), making game assets involves knowing how geometry shades and bakes, and requires…
As for the topology problems, you could look into remeshing workflows. I know the retopology tools in 3ds Max can work particularly well with hardsurface assets, and some artists have come up with a nice modeling workflow there, involving various modifiers to automate much of the process, and creating a clean output…