They are all different companies.
Ive been told by a friend that has a few Matorro tanks that the plastic disentigrates over several years. Henglong tanks don't seem to do that.
They all kinda look the same because they all copy each other or use the same molds from one manufacturer. Tagien does to some degree but they venture out and add more detail and metal parts and metal turrets that are different than the henglong ones. But their Sherman hull looks to be a copy of the henglong upper hull.