Are Mind Flayers just Vampires?

[Cespenar]

In addition to massive tone and genre differences summarized by the above posters, not even their inspirations are the same. Bram Stoker (among others) vs. Lovecraft? Come on.

With just a cursory glance at the Manual, one could come up with much more redundant pairings, in my opinion.

For example, do we really need every member of the classic list: kobolds, goblins, hobgoblins, gnolls, orcs, ogres, trolls...

Or ghosts, wraiths, and shadows?

Or ghouls, ghasts and wights?