I remember reading that TSR's excuse is that drow from in the north of the realms (i.e. Menzoberranzan) use "Lloth", while elsewhere it's usually "Lolth".
Some of the gods are known by different names in certain places (e.g. Talos is known as Bhaelros in Calimshan, and as Kozah in the Anauroch desert), so I guess it's at least semi-plausible
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BTW how exactly can you accuse Salvatore and Cunningham of mixing up gaming material in this regards, when these two people contributed more to the development of FR drow culture, society and lore than any other? Don't think their contributions are confined the novels either, they did much for the various drow-related sourcebooks.
Without Salvatore in particular, the drow would doubtlessly have been developed in an extremely different manner.