They don't need 4 umpires for that, a few years ago 2 umpires could ( and did ) pay free kicks straight away instead of balling it up, I agree free kicks will solve congestion quicker than any other change to the game. And it is the basic frees, incorrect disposal, tackling without the ball, high/low tackle and push in the back. We saw on Sunday however that the 3 umpires out there couldn't get it right or consistent, adding another umpire is just going to confuse things even more.
What it will ALSO do is add to the AwFL coffers as players spend more time running in to umpires than actually playing the game of footy.
PS I remember we used to joke in country footy about unfit umpires paying free kicks just to bring the ball back to where they were, maybe we should go back to 1 umpire.
