The Post pitching line is great when the pitchers have a few starts under their belts. This shows their previous 3 starts which are from last year. Some pitchers may have been tired, some may have been going real strong and the rest has slowed them. Plus those stats are also when pitchers were conditioned to pitch 9 innings and the win/loss was primarily theirs. In April not many pitchers go the full 9, hell you're lucky if you can get 6-7. So the bullpens matter just much early on as do the starters. I look at it as preseason football where you have to know what the second unit is going to do.
Trust me when I tell you that the NY Post pitching matchup is a great tool but like most systems it need a body of work for each season to be truly effective.