I know, I meant to say that although the trio's wands were chosen in that way, the others were not. But I think that since JKR was looking at the wood information to begin with, it's likely that she chose the wood for individual wands based on the properties they're supposed to have, though not necessarily by the Celtic calander/beliefs. (My comment was too long initially and I had to cut stuff out so IJ would let me post it, so maybe I wasn't clear, lol)