Use sic for Selene to auto cycle buffs and obey for Eos and practice micromanaging them. If the tank can't keep aggro from the fairy then something is wrong from the tank perspective. Ask them to flash or overpower more if they are losing a few in the pack that aren't being actively burnt down. If they are losing aggro on a mob while doing thier aggro rotation, they need a gear upgrade (and I'd imagine the DPSers are doing most of the tanking at that point).