I received mine, identified as breuseghemi too, and the group turned out to be both them and greeni. They were young, and the identification was made in the Congo by the exporter. I began to look for info on them as the differences developed over time, and realized the 'new' fish was the real breuseghemi, and the ones I had previously received seemed to be the greeni. I've seen both names applied to the same pictures, but fishbase has it clear, to me. So I thought I'd had breuseghemi twice, but it appears my old group way back when were greeni.
It happens a lot with uncommon or rare fish. I've had things here that turned out to be un catalogued species with no name. I had one African/Congo Basin tetra that was beautiful and lived for years, and that I had to send pictures of to the main expert at the American Museum of Natural History to get a name. Even then, they were "probablys".
The people on the ground in places like the Congo can be very knowledgeable, but there is so much no one knows. A three inch tetra caught for food may have slight differences from the one beside it in the net, but they travel under common foodfish names, in many cases. When we talked with fishers in Gabon, they were highly aware of the differences between the different elephant noses or Cichlids they ate, but they hadn't named the differences. They had no reason to.