All possible, my morrowind friend, with scripts programming
Unfortunately not (with the present MW scripting "status" - MWSE, etc.).
The only solution is to use NPC clones, but this requires not always possible "switching" between clones (black screen, magic effect, terrain obstacle, etc.).
Theoretically every NPC can have totally unique set of all MW animation sequences.
Here are available in MW "idles":
Idle
Idlehh
Idle1h
Idle2
Idle2c
Idle2w
Idle3-9
Idle (and hh/1h) is used by the game engine as a main transition pose and therefore cannot be used in scripts in case you want that specific NPC to do something else than idles: e.g. fight/run.
Idle2 (and 2c/2w), is a special case that is not working properly, see:
http://www.uesp.net/wiki/Tes3Mod:AIWander
Hence, only seven Idles left (3-9) are left. I guess proposed 5 (5,6,7,8,9) are fine (for me 6-9 works well).
Moreover, this (Idles' numbers) can be messed up in different MW installations (MW without addons and with Tribunal and Bloodmood), see:
http://www.uesp.net/wiki/Tes3Mod:Animation_Groups