Yeah, obviously from a pure combat standpoint, Claudia mops the floor with Kerry and Emilia. Valkyries exist for UP ramp, minor lightning rods, and cheap, easily replaceable duelists, either because you're swapping out lightning rods or dealing with rushes too early for some heavier units to be deployed without screwing your other deployments due to UP cost.
By the way, question for the veterans here: If I were to raise one Valkyrie, would you recommend Dahlia, Emilia, min-cost Kerry or -1 Thetis? Thetis' AW is niche, but very useful within that niche, Kerry is min-costed which is nice but not sure about slowing attack for sake of power, Dahlia gives Valks +7% attack which is tempting indeed, and Emilia, not sure what her ability is. Or would you recommend both Dahlia and Thetis? I guess a priority list would be better than just "keep one, bench the others" since I'll eventually be able to level them all, I've got my main team all AW and several backups as well.