By "centering the offense" do you mean becoming dependent on their scrambling ability and/or conforming to their poor passing skills?
Scrambling QB's don't necessarily have poor passing skills. Cunningham had a freakin' cannon of an arm, Colt McCoy is pretty deadly accurate, and McNair had the complete package throw wise (as did Young).
The problem is:
1. Play calling: If you have a QB that can scramble, you have to build the playbook around that. Running plays tend to be options and passing plays are either horizontal (to take advantage of the safeties and LB's run blitzing) or full on vertical (to take advantage of the safeties playing up).
If you want to see what happens when you put a pocket passer in a running QB scheme, take a look at the Texas Longhorns record this year.
2. Protection: Blocking for a pocket passer on a passing play is straight pass blocking. Blocking for a scrambler can become run blocking at any given moment. You need to have more athletic, quick reacting, zone block type O Linemen for a scrambler.
Again, look at UT this year to see what a pocket passer looks behind these type of O linemen.
3. Routes: A WR can go from running a route to having to block at the drop of a hat. Takes a different sort.
4. The clock in the QB's head: Where pocket passers have a natural "tick (first read), tick(second read), half-tick (third read and step up)/half-tick (throw it away/reset if pressure's not too great)" progression, scrambling qb's have a natural "tick (first read), tick (second read), half tick (third read/RUN!)" progression.
Change the QB and you change the whole timing of the offense.
Edited by Delhommey, 30 December 2010 - 01:09 AM.