"Coin Battle"?
Anyways, i dont know if this would fit a time match ruleset, but it would be great if there was an option (Inside time matches or on a new mode) where whoever caused the most damage is who gets the point. This way when there are multiple players no one person can idle and sweep in when the other two fought to high percents.
This would also prevent KO steals from the better projectiles.
This sounds more like a different mode though... I'll give it some more thought.