Yeah, I additionally run Cyrtanthus, and her doom-laser, in the fifth slot of that team as their 'executioner' to finish off any bigger targets that might survive the aoe-fest of the other girls. (It took me an embarrassingly long time to realize that party order does actually matter - always put your biggest aoes in the front of the party. This sweeps the little guys first so you don't waste your heavier hitting single target specials on them.)

I was under the impression that activation rate multipliers can stack, so I wouldn't mind clarification on that. Half the reason I picked up Nerune a while back was because her bloomed form also boosts skill activation rate(the other half being the excellent aoe special she has, combined with her useful map utility). It's also the reason I plan to eventually replace Cyrtanthus with Mei after her bloomed form becomes available.