Perhaps, but remeber that NPsare recoverable in part. Wholesale
bloodbaths will result in wholesale visits to the correct graveyard, and
likely new, macabre battles over bodies. Some bodies will be lost due to
inability to get to them (somehting that will likely be truer earlier),
and later... well, enemy bodies may be collected and stuffed in a tower
to rot. Yes, one NP each will come back ,after 8 turns. But for a noble
who is oathed, that's a 50% loss. If it's a mage, say oath-2, you are
looking at four NP minimum, of which you get one back. ANd if a long
term major mage gets it like that, the player may have 5,6,7,8 or more NP
in him. Or someone uses Last Rites, so that you get 1 NP (ONLY) back,
early, but the loss is nailed down, permanently
And even that assumes that the foe does not take the body and defile it
with necromancy so that you lose every last NP.
As for people quitting out and leaving nobles....
SWEAR allows one noble per turn to be sworn. So to quit out like that,
you'd have to play another 5-6 turns, on average. I can see people
deciding to play a turn, but most won't be interested in that, or willing
to spend the money. And I suspect that if Rich sees someone do nothing
but SWEAR for a turn or two, he'll watch.... Maybe see if it's the
extraction of a painful ransom, or something.