Does anyone recognize that Manning, in the playoffs, is a lot like the Texans on offense (historically)? Great between the twenty's (getting to the playoffs) but not great at sealing the deal (1 SB win in how many attempts, not to mention HFA throughout)?
As another member posted, Manning is very, very good at beating a weak sister. He doesn't fare as well against elite opponents, especially in the post season.
There's more to a team than who plays QB. Since Peyton joined the league, six teams have won the Super Bowl without an elite QB. I don't count Eli Manning (twice), Big Ben (twice), or Trent Dilfer as elite QB's. Manning was the beneficiary of two incredible catches and a butt ton of luck, Big Ben had the vaunted Steelers defenses and Trent Dilfer just had to manage to keep from screwing the pooch and not fumble the game away or throw a stupid pick (something I can see Schaub doing all to easily in the big game).
That doesn't include all of the particular big breaks a Super Bowl winning team got, regardless of the QB, just to get to the big game.
The Texans look fine. They have some issues, but all teams do. The Broncos are 2-0 against 0-2 teams. The Texans are 2-0 against 1-1 teams. If the Chargers and tAcks played the Giants, Browns, Ravens and Eagles in weeks 1 and 2 they'd be, at worst, 3-1 combined. The Eagles might be a surprise this year.
Every team is different every year.