Are you saying they are misleading because the defense didn't cause the fumbles with hits?
the "Cardinals are usually lucky with fumbles" premise starts with observation that fumbles overall are 50/50 propositions on recovery. Given the Cards have fumbled 22 times, but lost only 2 -- stands to reason that there were several/ many possessions they shouldn't have had, and that 10-2 record isn't sustainable.
i claim misleading because a shotgun snap hitting the ground before being picked up, a shotgun snap K1 falls on, or even a missed handoff in the shotgun will have a far, far higher expected self recovery percentage than your average fumble. Those three types of fumbles are ~15 of the 22.