Interesting concept, but I'm not sure how you're coming out ahead of pure pally. Ignoring static dmg bonuses:
Pure ftr: +24 Melee Power from Weap Focus / Spec feats, +21% doublestrike (Kensei cores), +1 crit range (Keen Edge)
Pure pally: +15 Melee Power from KotC (+5 from Empowered Smite for 10 secs), +10% doublestrike (Zeal), +1 critrange & multiplier (Holy Sword)
So it basically boils down to +9 MP +11% doublestrike vs +1 crit multiplier. For a weapon like, say, eSOS, I think HS definitely wins, particularly since crit bonuses affect Cleaves but doublestrike bonuses don't. But for, say, TF greataxes or mauls, the gap narrows.
But even if the DPS is comparable, that ignores all the other benefits of being pally, of course, like high saves and self-heals.