The Lesser Clown is referred to as a King Clown- completely different than a Butter Clown.
IMHO Butter and Lesser are not the same.
Allowing for the usual variations with the Lesser/Butter and Clown genes, I don't see any difference. The eye's look to be a different color, but other than that...
Lesser Clown
Butter Clown
Lucifer Sam, Siam cat...
Always sitting by your side,
Always by your side...
That cat's something I can't explain...