Also here is her back side, as you can see she doesn’t have that marking in the photo posted by TMoony at the beginning, she has more of a Greek tortoise scute design
You're right, sometimes Hermann's and some Greeks looks similar. Hermann's often get confused with Ibera Greeks (T. g. ibera). The easiest way to tell the difference is by looking at the plastron. Hermann's have (roughly) two black vertical bands whereas Greeks have larger splotches or even total black. Another, very obvious way to tell is the presence of a spur/nail/claw right on the end of the tail in the Hermann's. Greeks have no such spur. The shape of the head is also a big indicator. The pages below show good photos of the head and nose shape for each species.
Check out the eastern Hermann's photos on this page:
They probably came/descended from different localities where those colors/patterns developed due to evolutionary pressures. There are also probably color variations due to genetics or random chance.