Well, no, not if you accept the paradigm of B/X. Because in B/X there is no cookie-cutter fighter mage. Because there is no multi-classing.
(In B/X. there also aren't any Druids or Bards, and assumedly a mage is a magic user)
But let's look at AD&D (1e). In 1e, you have restrictions on the classes for certain species. Some classes are human only. But other classes (for example, clerics or halfling druids) might be restricted in terms of adventurers, but you can still find NPCs that species.
Which gets to the bigger point- "class" is an arbitrary construction, primarily used for adventurers. There are plenty of "clerics," (devout followers of a deity) but most likely do not have levels in that class. For that matter, there might be a large number of scribes who are quite good at scribing (or accountants quite good at accountin') who don't go on adventurers. Heck, maybe there is a John Elfnard Keynes who advises the King Elf on the multiplier effect of adventurers dumping dragon booty into the local economy, but he isn't likely to be adventuring.
There is no coherent society. There is simply a game that is being played, and what works for the players.
IMO, YMMV, etc.