*chuckles* I'm in a disagreeable mood today, it seems.
The major problem I see is not so much with the first idea, as it is with the second. You couldn't have adversaries spawn within spitting distance of one another - particularly since with the AI upgrade, monsters know how to use doors, or will bash 'em open if they can't unlock 'em.
Or, worse still, if the gnolls have crossbows. Without a clever script to change faction disposition when the doors open, the gnolls would simply cut the ogres down while they railed helplessly in their cages.
The second problem is a horrible exploit, particularly for classes like a Rogue/Shadowdancer combination. Two factions of not-inconsiderably-powerful creatures are within luring distance of one another. Our protagonist steps out of the shadows and does a little dance to grab the attention of a few members of faction A, and lures them over to faction B. She then does a disappearing act, and the factions duke it out. Meanwhilst, she makes her way over to a good vantage point, and sneak-attacks the weak and dying, getting the XP for the kill. In this manner, she could tackle enemies far too difficult for her to attack on her own. RP-wise, great, but because of the hack-and-slash XP reward base of the NWN engine, a grey-area powergaming tactic.
Personally, I think the best way to implement such a thing would be to put a "onPerceived" event that temporarily sets the warring factions to neutral, when they see a PC, in the style of "We'll kill you... AFTER we smash that little human/halfling/elf over there."
And now I turn to Terry Pratchett to close it out:
Racism was not a problem on the Discworld, because -- what with trolls and dwarfs and so on -- speciesism was more interesting. Black and white lived in perfect harmony and ganged up on green.
