My frontline has been Illya, Caster Nero, and Circe (with Rhyme, Mashu, and support in the back). Only using Mashu so I have have better CE's equipped. The Jeanne trio gave me a bit of trouble (had to use berserker supports), but other than that, no huge problems so far.
I just find it more fun to try using in bond servants first. If I seriously can't beat the quest with them, then I'll switch to effective ones just to get through the story.