It clearly makes it seem like equipment plays a huge role so if you're packing a lot of lv40 and lv40 event equipment, sounds like even 4* girls might work.

Also, the only things that matter with that is HP and skill activation rate (or what they even do). You get no abilities and might get 1 or 2 solar blasts... Girls that can heal might even be in the best position (but I have no healers above 4* yet... so haven't tested it)