Look at the length of the warhammer...
it looks much longer in game...
anyways winged mace weights 1.7 and has 70 reach
1h war cleaver has 2.2 weight and 92 lenght
what about winged mace with 20 longer shaft?
if weight counts is kilograms [it seems that way] it would be perfectly reasonable, considering iron war axe weights 3 kilos, yet can be swung perfecly fine.
and you all forget the mace dont have to be blunt, it could be long lighter weaker 1h version of morning star.