If the damage is lowered from 2000% then you might aswell get rid of "Throw Tomahawk" because the damage would be pointless. 2000% damage on a person with Usakoring = around 50k damage, so an estimate of 400% would be 10k? AND thats without full reducts which most people have ready in their inventory.
2000% damage + Reducts = Around 15k damage (From Experience)
Which is 30% of the damage left.
So 30% of 10k = 3k...
and Im sorry you can't expect to come close to beating anyone with that.
So in my opinion, the 2000% damage is fine...
& As for pneuma : MasterSmith's need a ranged defence mechanism, up against a hunter or a Stalker they struggle to survive as it is, Let alone without pneuma or a damage reduction.
I think the Cart-Termination Boost should be removed though (+50%) and placed on the WhiteSmith Oriental Sword, which is (20%) so that a different weapon is required for each build.