I'm saying that "if a pitcher gives up few earned runs, that is a successful outing for the team", and also saying "that does not indicate that this pitcher is likely to repeat that successful outing for the team".
Bottom line, success = wins, which is giving up fewer runs than your opponents. Naturally, however, you want to have a guy on the mound who is the most likely to repeat that success which, according to the peripheral stats, Sanchez is not (but f*** if he doesn't keep mocking the s*** out of those peripherals, somehow...)