1st, I would be very suprised if the F-35A isnt produced in 1500+ numbers. It is being used as the justification for halving the numbers of F-22A's to be produced. What wil justify cuts in the F-35A production line? Specially when F-16's and F-15's will be falling out of the sky?
Yes there are alot more F-35A's planed then F-22A's and they wil be the primary fighter, just like the F-16 is now, however they will be doing a whole variety of tasks like SEAD, DEAD, interdiction, CAS, (tactical strike), and counter C4ISR and air superiority. F-22A OTOH will be doing just 2, air-superiority as the primary (which includes escort and CAP) and HVT strike. F-35 will be the primary tactical strike asset in the USAF, F-22A will be the primary air superiority asset.
Even theough there will be 10x more F-35A's in the orbat, they also have (practically) 10x more things to do. In any theater F-35's will be going about "down and dirty" doing all maner of things, takeing out radars, hitting tanks and intrenched postions, destroying bridges, attacking lines of communication, doing anti shipping, hiting HVT's ect ect. F-22A's on the other hand will probably hit some comunication junctions or the like on the first night, and then provide air superiority for the duration of the campaign.
Its extreemly unlikely that the USAF would be deployed to a theater were at least 1 squadron (probably wing) of F-22A's are not, therefore the A2A capability of the F-35A will not be as improtant to them as the USN or partner nations who will be useing the platform astheir primary air superiority and strike assets. Therefore they may be the driveing force behind the 6 AAM capability rather than the USAF.