Difference between 2H Blunt and Limited (Staff)

[Ghaleon]

without searching through the dats, can anyone tell me what determines the difference between a quarterstaff and a battle-hammer?

In nightmare, they are both 2H blunt, worn nowhere, with natural under armor. Unless their is some variable I'm not taking in account.

Tested with a lvl 1 mage with 100 str. Only the quarterstaff was wearable.