The longer you stick with the same system and allow Kubiak to develop and build the Texans slowly and patiently, the more time you give Peyton and friends to crack Kubiak's code. The Colts aren't just on top of the division because of player talent, they are perennial winners because Peyton isn't really challenged anymore by the 3 other teams in the division. Sure, you could draft a RB and become a great running team like Jacksonville in the Fred Taylor/MJD days or the Titans currently, but that's not likely to get you to even split games with the Colts. It's a rare situation that your path to the playoffs goes through a QB that is so smart that your entire system can become obsolete in a matter of a few years, but seriously, a new coach would pose a greater threat to the division leader, and the Texans have obviously already dedicated their plan towards stopping Peyton (i.e. Mario Williams over Reggie Bush) and trust me, Kubiak's system does not scare the Colts.