I would also posit that lefties' advantage basically disappears once you get to a certain level in fencing. Past some point, it's basically all just footwork anyways, and your orientation doesn't change the distance of your target (foil and saber at least, can't comment on epee as they seem to just kinda bounce in place a lot even at Olympic level).
Can confirm. My brother fenced at a club that had a lot of lefties. All the righties got used to it quickly, and had no real disadvantage when playing against lefties.
I could easily see the difference in tournaments with other clubs that were not used to left handed players.
