Tests were conducted on Rocs and Greater Rocs in Nighon (MM7). Stunning and paralizing works OK both with single mace and with mace-sword combo. Paralize effect lasts exactly for X minutes, where X equals to Mace level. Same effect while wielding mace-sword combo. (mace-dagger combo not tested)

So I think that special Axe GM bonus (halving Monster's AC on a successful blow) may work.