It can be very confusing, and that is why the "Common Name" thing has really gotten out of hand. The wholesalers are bad at slapping a color behind a fish's name to try and help sell it faster. We are to blame too -- we are the hobbyists who can't keep our records straight, forget what we actually bought, spawned and raised, and screw up the names when we sell them at the Auction. There are many new Aulonocara coming in from new collection points, and they are so far behind on descriptions, that it is not known whether some are just coloration differences or whether they are actually a different species.
Aulonocara baenschi - is a yellow peacock with some blue in the face. Nkhomo Reef is a collection site, and is near Benga... Note the eyes, they are much larger, because they are found at a deeper location in the lake. Also, the nose is curved.
Aulonocara sp. maleri - The "maleri" is a gorgeous fish and has been called everything under the rainbow... It is the original Sunshine Peacock. Chipoka is a collection site, as well as Maleri. So it is possible that you could see it as Aulonocara maleri "Maleri", which means that it was collected near Maleri Island. Color is in the eye of the beholder; a lot of people call yellow; red, or orange; red.
The maleri is most likely the fish used in the line breeding to come up with the Rueben Red, German Red, Ruebesence, etc. This is how desperate wholesalers are to sell a fish; they are trying to "Latinize" the Rueben Red so that people think it actually came from the lake, which it didn't. It isn't a stuartgranti either, there is a lot of junk going around called maleri today, so you want to be sure that you get your fish from a reliable breeder.
Aulonocara stuartgranti - is a complex of Aulonocara, here is how Steve Lundblad explains it:
The only ones I believe to be in the true stuartgranti complex that are currently available in the hobby are the ones from Chilumba, Mdoka and Ngara. I believe the second complex in the northern portion of the Lake contains the Usisya, Maulana and the Blue Neon which occurs in Tanzania and Mozambique. The maleri types which occur at Maleri Island and Chipoka Island, more specifically called Chidunga Rocks are a separate group of fish all together, and should not be included in stuartgranti, I believe. But then, that's just my opinion.