Felon said:
You've made this comment on past occasions and it always makes me wonder why you say this. While it is true that humanoids can be advanced with character classes (as many monsters can), goblinoids, orcs, and other races primarily remain as low-level threats. And halflingss, elves, and dwarves tend not to be creatures that players are going to fight at all. Humans, of course, tend to be the exception.
I agree that halflings, elves and dwarves don't appear that often as opponents. (They're correspondingly less represented in DDM, although elves and dwarves tend to appear more often due to the alignment structure that you mention).
However, once you compare humanoids in general (orcs, goblins, humans especially) to any other type of monster, they tend to outweigh the use of those monsters significantly. (The exceptions, ogres, giants and lesser undead, are also pretty common in DDM).
At higher levels, what tends to happen is that the
range of monsters multiplies dramatically. At low levels, orcs and goblins are popular opponents. But what at higher levels? I suspect that the variation is much, much more at these levels. Some campaigns concentrate on giants, some on aberrations, some on outsiders, etc. Some just use any old monster that comes along.
The result of this is that a common ground of monster selection is no longer held. Of course, there will be some convergence on the monsters in the original Monster Manual, but variation is much greater.
Look too at the numbers encountered. One behir. Ten goblins...
There are certainly some figures in DDM that should be more common than they presently are. (My poster boy for this is the bearded devil; I expect it to be redone as an uncommon in
Blood War) Certainly, Hill Giants and Ogres are much more common now than they used to be.
Does the DDM alignment structure distort the reckoning? Certainly it does. Then too, DDM also caters for people who buy only a handful of packs. Three or four packs of
War Drums should net a group human, dwarf, elf and halfling miniatures for their PCs.
One interesting factor that I've noticed over the past 18 months as I've been DMing RPGA adventures: Humans make up a great number of encounters in Living Greyhawk and Mark of Heroes.
Cheers!