I understand what you are saying. But if you look at how the teams shaked out in runs scored in the AL, for example, the best teams were from all over the place. Yes, the Red Sox and Yankees were 1 and 2, but the Rays and Orioles were just 7 and 8. Better than other divisions, but not markedly so. Besides, if a pitcher is really good, he should be able to get outs no matter who he is facing or where he is facing them.
I agree with you that other measurements give a more complete picture of performance, but if I had to choose one metric for pitchers, its ERA, and Lackey was SO far behind there that he could not possibly make it up no matter what other measurements you use.
BTW: did you represent OJ Simpson too?