Agreed.
A while back I looked at all "running QBs" - which I defined as guys who've rushed for 400+ yards/season - and longevity. The results were not promising, as most broke down by about age 32. And yes, I got a ton of comments pointing out that there was an explanation for all of those. But a pattern is a pattern.
I think this is the best case scenario for Josh. Let's call it the John Elway Aging Curve. If anyone can do it, he can. But its no sure thing.