I mean I don't know what kind of testing this is though
We're testing using sword two handers, something they'll never achieve anyways. Even if a staff weapon was introduced, it wouldn't be sword levels, and then would have to be class locked too just in case. But seems like a hack that way.
I'd rather just boost their class damage overall to about that damage as posted above (or slightly less as I don't see that he STR buffed himself) rather then faffing about with making class only weapons that are this specific. Even if it was a two hander staff (???) it's only 1/1 to 2/2 more which wouldn't give them the damage you see above. That is if we even do it.
Really what you want is a better class damage modifier.
Two handers promote nothing as if two handers are the best weapons for them, that's all they'd go for. They only have 'one weapon' and no shield, so introducing a two hander with no reason not to use a two hander (because they don't use shields) makes no real sense. There's an actual reason to use two handers vs a shield as it's more damage vs more defense.
Simply making their str modifier better would be the real solution here. Necromancers can use daggers, something which doesn't get used anyways currently and would probably assist them somewhat.