Hey, so last night I went into Karazhan with one of the oddest group make ups ever. In no way did our group look ideal but we ended up killing everything except Nightbane and Netherspite (mostly due to time constraints). Group makeup was:
Our normal group is a little odd, but not quite that odd. Usually something like:
x2 Holy paladin
x1 Holy priest
x1 Prot warrior
x1 Feral Druid
x1 Balance Druid
x1 Ret Paladin
Rogue, Mage, Lock.
I think the strangest I've done it with was uh
x1 holy pally
x1 Resto druid
x1 Holy priest
x1 Resto/feral druid offtank
x1 Feral tank druid
x2 Balance druid
x1 Ret paladin
x1 DPS war
x1 Mage.
which did Moroes --> Aran and then went back for Attumen after Aran died. It was a normal group the second night.
Our very first reset (well, the first two resets) we used this group and killed all but Netherspite and Nightbane. Happened to also be the server first for all of it.
Honestly, it's probably our smoothest group apart from R&J which we didn't fight and Nightbane which we'd need one of our 0 dwarf priests for.