Why the Multiple 'Clans'?

[Lantarion]

I am reading BoLT1, and I noticed that many different 'clans' of Maiar are mentioned, who help the Valar in their duties. E.g. for Manwë the Mánir and Súruli are mentioned, and for Ossë and Ónen (Uinen) there are three: the Falmaríni, Oarni and the Wingildi.
Apart from these, there are the "sprites of trees and woods", the Nermir, Tavari, Nandini, and Orossi!

Why so many? The little spirits and leprachaun-type creatures I understand: but if there are Maiar who help the Valar in their labours why weren't they just set into a single group each? I realize that each 'clan' has its own seperate duties. But do you think this separation was needed? And did Tolkien later abandon these theories?

[Niniel]

Maybe (this is just a wild theory and not based on anything) Tolkien had conceived the Maiar as similar to the Christian angels; who are also divided in different classes (9 if you read Dante). Ot he had based them on the Greek/Roman mythology which also contains all kinds of nymphs (Dryads, Nereids, Oreads) and other godlike creatures. I tbink he abandoned them either because it was too complicated to give them all a useful function in the mythology, or because he wanted to make less comparisons with other mythologies like the Christian and Greek/Roman ones.