"It was left up to the scorekeeper." ...Exactly why it doesn't work as well.
MLB Language: If a ground ball goes through a fielder's legs or a fly ball falls untouched and, in the scorer's judgment, the fielder could have handled the ball with ordinary effort, the official scorer shall charge such fielder with an error. For example, the official scorer shall charge an infielder with an error when a ground ball passes to either side of such infielder if, in the official scorer's judgment, a fielder at that position making ordinary effort would have fielded such ground ball and retired a runner. The official scorer shall charge an outfielder with an error if such outfielder allows a fly ball to drop to the ground if, in the official scorer's judgment, an outfielder at that position making ordinary effort would have caught such fly ball.
Everyone's definition of "ordinary effort" is different, which makes OB% a more apples to apples comparison. It sounds like we as a conference group have a hard enough time getting the OB% correct. I can't imagine throwing errors in there.