For each version of Golden Axe here (
Coin-Op,
Genesis,
Master System) I think the wrong number is being used for the counted score. The game sets a "Total Score" based on enemies killed, but then it uses some formula based on the number of lives used in that playthrough to determine the player's "Strength." That Strength number is technically the true score for the game. That's the number that should be counted when determining the ranking of the players.