Why has nobody linked this thread yet?
http://www.project1999.org/forums/sh...ad.php?t=24405
Best explanation I've ever read. It would seem to suggest that having a hybrid in group should NOT lower the exp gain for everyone else. The ONLY thing the game cares about when it splits up the exp from a kill is the TOTAL AMOUNT of experience each member has accumulated since level 1. Obviously, at the same amount of total xp earned, a hybrid will be a lower level than a normal non-penalized class, but they will still get the same amount of exp per kill.
Here are two duo scenarios to explain further:
Scenario 1: two non-penalized classes of the same race with the same amount of exp are killing shit together. They each get equal amounts of exp per kill and will stay the same level forever.
Scenario 2: a troll SK is grouped with a human druid and they currently have the same amount of total exp earned. The troll needs 68% more xp per level than the druid, so as it is now the druid is a level or two (maybe more) higher than the SK. They STILL get equal amount of exp per kill even though the troll has innate penalties and the druid is a couple levels higher, because they still have the same amount of TOTAL EXP. This means it takes the SK longer to level up than the druid but they will always have equal xp totals and get the same amount for every kill.
TLDR; Having a hybrid is your group is only going to significantly affect your exp gain if they have significantly more exp than you and thus are taking a bigger slice of the exp pie. Keep in mind that hybrids (especially troll SKs) can have MORE EXP than you even if they are 1-2 levels below you.
This is how I understand it at least, feel free to correct me if this is totally wrong.