Honestly, take the homerism out of your head and think about things rationally for once please.
19 games over .500 for 4 guys is being on the low side with the yankees. You have to consider that wins for the sox starters are going to be tougher because they dont have a closer at this time and the bullpen is awful. Consider that the yankee rotation was 32 games over .500 last yr and it sucked (to put it nicely) is more an indictment on the offense and closer than anything. The sox have problems in both areas right now.
At the same time, Igawa has a history of being over 200IP which is essentially what he has done for the past 6 seasons. Johnson has done one thing well in NY, and that is eat innings (over 200 for the 2nd time in 2 yrs for the yanks).
As for the yankees pen being a question mark. Dude, have you seen anything the past few yrs? Have you watched the sox pen crumble or have you blocked it out of your mind. The Yankees have a lights out closer whose decline is always predicted yet perennially proven wrong. They have a league average set-up man and one of the best "utility" relievers in the game with the emergence of Proctor. Those 3 guys will have heavy workloads. Bruney will be used to supplement. In case you had your head in the sand, you would have seen how great he was in his time in NY. He was cut in Arizona because his velocity dropped by 10mph. Why? Because he developed dead arm in ST and was worked too hard early on. Then he goes to NY and starts throwing 98-100mph again and puts a 0.87ERA on the board in 20.2IP. Britton threw over 50 innings in the AL East last yr and had an era in the 3.5 range. I just rattled off 5 names that had success in the pen for the yankees last yr. Oh, and Myers was a solid matchup lefty. There is 6. How many will the yankees need out there? They are said to be entertaining the thought of 13 pitchers, so long men/mop-up/spot starters in Karstens and Rasner make the pen and voila, you have 13. That pen is stacked and then there is Beam, possibly Villone, Cox etc getting ready. That pen is loaded.
As for every yankees starter over .500, well, that is more because of the offense and pen than anything else. RJ's era was 5 last yr and he was well over .500. Also, the yankees had 3 guys at or above 200IP last yr. The addition of Igawa, a perennial 200IP pitcher in japan, should make that 4. There is precedent.
For the sox, you have Schilling and Beckett who will surpass 200IP barring injury. Papelbon is coming off an injury and being stretched out from closing, he isnt hitting 200 innings if his life depended on it. Matsuzaka made 200IP once in the past 5 yrs, so betting on him doing so in his first yr in the ALE is shaky at best. And the funny thing is, the one guy I would peg for 200IP easy is the perennial 200IP pitcher (when not having a freak injury or being in the pen) is wakefield and he wasnt pegged for 200IP. Call it what you want, but I think I was a lot less biased in my predictions than most.