I find myself agreeing with Zisa here. Give it a little speed, take a chunk of it's damage, lower its requirement to say 13 str (so it keeps the difficulty-non-divisible-by-3 attribute), give it back it's polethrust (none of this 17p MWkatana BS either) and call it weeaboo.
I agree that the Nodachi should not just be a slightly different version of the War Cleaver as it is now.
Stats coming at you;
War Cleaver
weight: 3.5
difficulty: 15
speed rating: 92
weapon length: 120
swing damage: 45 cut
slots: 2
Can't use on horseback
Unbalanced
Nodachi
weight: 3.5
difficulty: 16
speed rating: 91
weapon length: 122
thrust damage: 0 pierce
swing damage: 43 cut
slots: 2
Can't use on horseback
Nodachi is worse in all except for a paltry 2 length and it isn't unbalanced.