I don't think there is a problem with the products.
Provided the content sellers legally own the rights to the footage, they can edit it however they want and sell whatever versions they want as many times as they want under whatever studio names they want at whatever price they want. Many producers on this site are doing variations on the same theme.
Of course the producers will say they need to do this to obtain a return on their investment. Customers can see for themselves what products are available in the clip store and make their own decisions to buy, or not. Caveat emptor.
The problem I see is that models are not rewarded for the producer's enterprise.
The models are probably paid a flat fee to shoot for as many hours as the director can get them to work, saying he needs the footage to make "the scene" which they signed up for. Then later the footage can be diced and sliced as thinly as possible by the producer and maybe sold as multiple different versions in different markets.
So, I think Giorgio's idea of revenue share payments for models has merit (in some circumstances). So long as the model has a reasonable level of trust in the producer to operate the revenus share scheme fairly. And so long as the agreement covers all future sales of the footage however it is diced and sliced.