Actually Rajah, Fudo has been shown to out parse both Unji and Unsho in the offhand.
They are not "clearly better" since you are obviously basing your assumptions on the idea that lower delay and ws modifiers >> 7-8 dmg along with +crit%. If you're going to go declaring that something is "clearly better", perhaps you should get some data to back it up.
The general consensus is the even though Fudo comes out slightly ahead in a parse, that you can offhand Unji and Unsho and still do just fine.
Senju/Perdu is the best combo imo. If you're lookin for the crit bonus you should off hand the Rai Kunimitsu over this one, w/ the wide selection of katanas this just finds no place. So many katanas are better than this one!