It is advantageous in ancient combat though. When everyone is carrying a shield with their left hand and their sword on their right hand, the leftie can strike their relatively unprotected opponent's right shoulder, unless the opponent is in formation and has an ally to its right.
Also helpful when storming a tower; spiral staircases are generally spiralled to give a right-handed defender the advantage against a right-handed attacker
But as long as neither you nor your opponent plan to fight in formation, it's all good! This "fighting in formation" thing probably isn't going to catch on.