So they're trying to make it so you don't have any all caster or mostly caster runs with the sp drain mechanic. Can simply have a high healing amp fvs or wiz-rogue/wiz-monk with high saves "tank" Lolth and just be healed by 1 of the 11 other casters when needed. Meanwhile the rest of the casters destroy the trash from cover.
Good attempt, but still irrelevant. Absolute class rolls ("hey, you fvs/clr, get back behind that rock where you belong so you can be my babysitter") are not so much good and people will always find ways around them.