Stances/Invocations make this game feel almost like a modern mmo. Unless you're cruise controling blues, when shit hits the fan you're often doing so much actual decision making beyond just hoping your spell goes through or your attacks hit more to save yourself. If anything this is the one thing I think that makes it pull ahead of THJ which was mostly an "auto-attack save me" type game which most of EverQuest really is.
Theory crafting some stuff and I don't know there's a bad combo I can think of outside of maybe something like Ber/Wiz/Enc where you'd have no way of really getting your health back IN combo besides your enchanter pet being a paladin. Every other combo I've thought of has good synergy, especially when invocations overlap.
For instance a Ranger/Dru/Shaman sounds like it'd be weird and bad? Nope. You're literally DPSing in melee (or ranged stance) the entire time BLASTING DD's and DOT's with Divine Invocation on to heal yourself for 100% mana cost ever cast. You could literally be a cleric/dru/shaman and be a shadow priest just nonstop druid nuking and still healing yourself/your party.
Very impressed with those two, stances and invocations. Definitely a great addition.