The other issue with tanking is that players hit free agency so fast in the NFL that, unless you have no talent on hand whatsoever, or are able to tank for just one and only one year, it can quickly get counterproductive.
If your M.O. is to let most of your top FAs walk - because they will get offers far in excess of their on field value - then an extended tank means losing talent as you are trying to add it, like running on a treadmill. Worth it if you tank for one year and land a cornerstone player, I guess. But if you don't you might be setting your franchise up for an extended period of weakness.
My brother's thoughts on Cam from a physical perspective.
I think health is the only question mark here, but it is a significant one.
I think Cam is here for one year on a make good deal, to rebuild value in himself, as other mid to late career FAs have dome with the Pats. The fact that he opted for this kind of deal, and the Pats offered it to him, suggests to me that healthwise he is OK - or at least that both parties think there's a good shot that he can be OK. I think if he thought was toast he would have sought a multiyear deal with some guaranteed money from a bottom feedimng team with bad management, and I doin't think the Pats would have even bothered with a cheap flier on him if they believed he was done.
Assuming there is a season at all, and that Cam is healthy, I think he starts, plays well, takes the Pats to the playoffs, and cashes in elsewhere in 2021, getting a big deal that he ultimately does not live up to. But he may ring up his best season numbers outside of the MVP year.
I don't think they are sold on Stidham as heir apparent to Brady, and so I don;t think they are overly concerned about harming Stidham's development.