I had a play with the league totals as well, and thought I had got them on the right track. I had forgotten that I wasn't playing with so many teams as in real life, although I don't know how those teams omitted affect each stat. The only thing I was way too high on was batting averages, but then after four years something weird starts to happen.
The overall batting averages and the overall ERA plummets like a stone for no reason, in turn dropping the home run leaders down by a third, but for some reason the best player batting averages go up to over .500.
Oh well.