While I can’t make any promises, I can say we have been discussing ways to improve traitstone variety in PVP.
Thank the lord thank the lordddd!!! 
Pardon me for necroing this thread, again.
For those who still want the benefit of tribute from Whitehelm but also want to help people getting more variety stones from PvP, please consider this method: Change your home kingdom to WH only when your tribute pop up. Then change it back to other kingdom. It only cost 100 gold and a few clicks. Thanks 