Well, you have to take into account why they were struggling. The Cubs chose to go with Rusch last year even as he got lit up and Hill was fine. Speaking of Rusch, Glendon was in the league earlier, but sucked big time. At 26 he had an ERA around 5.80, but had been given chance after chance. He then had a couple mediocre years before declining. Likewise, Moyer was given a shot before 26, but he sucked in that extended time. At 26 he started to get better. Hill is struggling to get into the majors because the Cubs have decided to go with other pitchers. Kenny Rogers came in at 25, but was a reliever for 2 years. He was struggling to crack a rotation into his late 20s. Jon Lieber was given some time at 24 and 25, but he wasn't given a full season as a starter until 27. Hill hasn't been given a chance to struggle into the majors, which is something countless pitchers did in their mid 20's.