I say Tung, because he's an old guy, and the Age is but a Number Postulate of Fighting Games clearly states that power and/or fighting ability is directly proportional to age and infirmity. So a guy who's over 100 and can barely stand up, let alone walk, could conceivably take on the combined forces of North America and Europe without breaking a sweat. (The forces of Asia are a different story; there you're talking a numbers game unlike any other <IMG SRC="smilies/biggrin.gif" border="0">)
Plus, Tung, I believe, is a kung-fu master. Kung Fu is one of the oldest, if not the oldest, fighting style in history (besides the classic "bash his head in with a club" style used by many cave-dwellers of the days of yore). And its name means "person of the highest ability."
So I say Tung all the way and back. And that's not even considering the "muscle Tung" ability. Unless Mai were redesigned by Go Nagai as a mech (breast missiles), she wouldn't stand a chance.