Let's look at 1997-2000, Pedro's prime:
Martinez: 77-25, 2.16 ERA, 0.93 WHIP, 11.5 K/9
Johnson: 75-31, 2.68 ERA, 1.09 WHIP, 12.3 K/9
Pedro's numbers are better, but RJ was definitely not average--probably the 2nd best pitcher in the bigs in this time.
2008: 11-10, 3.91 ERA, 1.24 WHIP, 8.5 K/9
2005-2008: 53-36, 4.31 ERA, 1.21 WHIP, 8.5 K/9.