Imaro
Legend
But, see, that's what I don't understand. You probably don't have any problem with several different kinds of Drow - Eberron Drow and Forgotten Realms Drow; several kinds of ogres - Dragonlance Ogres are not standard ogres; umpteen different liches; Rakshasa have had a few different takes; so on and so forth.
Why is it a good thing that we make creatures unique for settings, except when we go planar? Why is it a good thing that we have multiple different Rakshasa, but, we must not have alternative back stories for Vrocks?
Look, I'm not talking about totally different creatures here. I'm simply saying that single creatures can have multiple different back stories and canon that are linked to different settings. Thus the stat block for an orc in Greyhawk is pretty much the same as the stat block for any other orc. But, no one would mistake a GH orc for an Eberron one.
Maybe baseline Vrocks are soldier demons. Cool. Forgotten Realms Vrocks are attracted to magical battlefields and feast on mages. Eberron Vrocks carry plasma rifles. I dunno. I don't really care. Just so long as we are having one single idea for a creature constantly forced front and center and all other ideas discounted as Poor GMing Choices because they don't fit with someone's preconceptions.
But we have multiple demons and multiple devils... What you seem to be asking for is multiple wood elves... or multiple types of blue dragons (in other words multiples of a specific sub type of a group). Which is so niche... I don't think most people are willing to spend a significant amount of money on.