There's no question the warhammers are powerful, though I will add that they still have weaknesses if you run out of stamina or time a swing wrong and an enemy gets in between slams. The issue is that having only one attack is boring. As an expert on hammers, I can tell you there's a lot more that they can do besides smash into the ground. Maybe they could give it an upward swing that has normal damage but even higher knockback and can only hit one target. Could be fun for playing golf with greylings.