I have the polished wand - http://prntscr.com/9ef6vd
My swordplay ability says 5% - http://prntscr.com/9ef72c
I am quite concerned about this seeing as the other crusaders increase the swordplay ability by 20%.
As you can imagine the fact that I am getting;
5% + 4*(20% * 5%) = 9% (see http://prntscr.com/9efbkm)
instead of
7.5% + 4*(20% * 7.5%) = 13.5% makes QUITE difference on my click damage.

*EDIT* Even if the 20% swordplay increase would be based on the base swordplay skill - before the polished wand's effect - the 9% I have is still 2.5% too low :-s