My struggle with Kop Rukk and Drakfoot Warclan has been the core cost of the two battalions plus the min character tax, which doesn't leave a lot for boyz. Units of 10 do not seem to work, and even units of 30 do not really put out enough damage from what I have experienced... and lawnmower units just chew through them. The only time that I get decent damage (at best) are from spamming spells from 4-5 wizards or from using big stabbas... would love to hear if anyone has had success without using the Kunnin Rukk arrow spam.