There are more than three Allied aces to make claims against three different Axis countries. Off the top of my head some Australian pilots are - Clive Caldwell. Bobby Gibbes, John Jackson, Bob Whittle, Pete Turnbull. Most of these have German Italian and Vichy French kills to there name, some with Japanese. No doubt there are more (I'd have to look into it in more detail), plus I'm guessing a heap from the RAF.
HTH