Nothing wrong with keeping a P. edulis AKA the Dwarf African Bullfrog. The situation to understand is the overall confusion on differentiating the 4 recognized Pyxicephalus species; and couple more that are either variants or unrecognized species at the moment (i.e. the Tanzania African Bullfrog). In the past the Mozambique Bullfrog (now P. angusticeps) were being sold as Dwarfs too.
Since babies/juveniles are similar to the untrained, you could end up with a different frog than what you wanted (i.e. a P. adspersus AKA GABF) so the main thing for those that want a giant and nothing else, is to learn how to ID and only buy a specimen they can see and choose after examination.