Well as the other guy stated, butters and lessers are pretty much the same mutation but proved out by different people. Then they were named. Kinda like bananas and coral glows as well as phantoms and mystics. Even the latest "tangerine" from ralph davis is looking like a new line of the same genetic morph already established "orange dream".
There are still people out there who consider them different morphs, so it's only proper to name them for what they are. Their combos look the same, they have the same super, they are identical in every way. Obviously no 2 will look the same.. Heck 2 butters can look completely different from each other..