I use this line up and I'm quite satisfied with it... deals around 0.85-0.9 % dmg per run. Main Mooded to +65 %, while other ninjas to +25 %.

x Water Main - Water Clone
x - GNW Ten-Ten - X
Mei - Iruka - X

Tallents : 4-3-4-1-1 Summon: Ton-Ton. What I like the most about this line-up that it works great on auto.
As for you - try switching Mei to Darui, he might be better with his double attack and 10xchase, but his barrier won't buff Iruka.

Well, than in his case it would be better to replace Mei with Darui, who would also get buffed by Mifune. And what dmg do you deal in %?