I can predict possible issues though, not so much with balance though that could happen, in regards to the fact Axes and Swords share the slashing weapons tag. That a future uniques, and coding, if the code reads from that slot for 2H Slashing weapons then allowing it in the 2h Blunt side while preventing 2 of the same type.
Well probably more time. effort and resources than its worth tbh, especially right now.
But heck its a free idea to support a game i enjoy, something worth considering though as i thing Ancients oath and Crimson are a match made in Hell 
but HH hammer brings the heat also