Yeah, 21/18 would be better for anyone competent in melee already. No reason not to go low WM build for pure infantry. Swing speed does matter a little bit in terms of recognizing when your swing would beat out your opponent's, but the swing animation has much more of an effect on that. All of my pure 1h dream builds involve no WM at all.
I wear heavy armor and my effective wpf comes out to ~100 from 131 with 1h and I still swing fast. Medium armor with 111 should be just fine.