I've got a rightie that prefers the left. And I've got an 'either' that doesn't seem to like the left (or just had a bad couple of games).

I had a leftie that came with my team that only liked the left - huge slump in middle or right. So I had to put him on left even as a lone striker.

Individual traits? Chance? Who knows. Just fiddle about and stick with what works.....until it doesn't.