How to beat a strength build with a crushthrough mace as a 1hander
http://www.youtube.com/watch?v=3iJTi_OITEo
If you can land the kick, great but most people can't do this. I'd say get in a side swing duel, make sure your positioning is always on the opposite end where your swinging so your hit lands first if he dares attempt an overhead. Obviously you still have to block if he decides to do a side swing but make him pay if he ever tries his crushthrough attack. Granted, this won't work if he's working together with someone and if he's a good mauler he probably is, in which case you're better off running away.
I am telling you though, there is nothing OP except teamwork. Put shielder + shielder with spear together and it's the most infuriating combo. At least with a shielder + mauler they give you the decency to die quickly.
Two-handers in general are rather worthless. Make two two-handers work together and they have a much bigger chance of TKing each other compared to if one of them was a shielder. You also don't get the benefit of the shielder able to completely tie up whoever you're gang banging. The ability to hold up right block and just let the shield take blows while the other guy does all the damage is ridiculous. Mauls are good I'll give you that especially deadly when paired with a shielder, but don't lump in the rest of the two-handers with them. I feel like that would be saying lancing cavalry is OP therefore we must nerf polearms.