The code seems to check the NPC stats just like any other.
So dropping any stat on an NPC will impact them. Hell, you can use rot + damnation and the NPCs will die if you can get them to 3 con (all NPCS have 25 con though I think) no matter what.
Nuke STR and they hit softer.
Nerf the dex on an NPC that dodges well, and you'll notice it dodges far worse.
Battaglia nukes dam roll of enemies, and it clearly affects NPCs in how hard they hit.

Keep in mind, that NPCs also do get the stats benefit of gear they have as far as I know.