How to turn a cupcake team into a Playoff contender?

[DaNextPhenom25]

For the past couple days I started a franchise with Madden 10 using the Rams and the Chiefs in another. After 5 or so years I got them up to a 88 overall, had a few playoff appearances, and one Super Bowl loss. I was satisfied with the results I had made with the Rams, after I rebuilt them they had consistent winning seasons. Btw I am simming all the games. But with the Chiefs franchise, they just couldn't find a way to stay above .500. I had an outstanding o-line, great defense rated 89, solid HB's, a couple above average WR, but lacked in the QB position. Cassel's rating dropped to a 79, so I had to draft a QB early in the draft and made him start, he turned out to be an 80 year 2. My question is what did I do wrong with the Chiefs, they were an 87 overall, 84 defense. I thought maybe the coaching staff had something to do with their terrible records, so I fired everyone and hired new coaches, that didn't help either. I'm wondering if the HC rating has any effect on the team's performance. Unfortunately when you hire a coach, you can't see their rating, which makes it hard to get a god coach. I'm not sure what else I need to do to make them successful.