Yes, just make bastard sword 1 slot weapon. Or Bec. Or Spear. Because atm Mace better than Fighting axe and cheaper than Langes messer. There are just no more choices in 1 slot 2H weapons.
Possible other 2h weapons that could be 1 slot IF the knockdown was removed from the mace, from a guy who's main is a 1h/pole hybrid and generally thinks 2h is eeez mode, but nontheless accepts that arhcers want to use 2h weapon instead of 1h no shield:
Axe, Two Handed Axe, Bastard Sword.
Although don't listen to me as I have this weird tough that more 2h/pole weapons should be 1 slot, more 2h/pole weapons should be 3 slot and that more 1h should be 0 or 2 slot.