Exactly. I'd add BB puts a ton of value in risk management and will be damned an injury to TB12 derails this team's SB chances.
I agree with your whole post. BB puts a lot of emphasis on what's right for the team and therefore doesn't want the team's ability to compete compromised if they have to play their backup QB. I think he's commented openly on this aspect of team building elsewhere.
However, I think it's worth noting that BB is playing a pretty risky hand if he's turning down the kinds of offers we've been drooling onto our keyboards over.
Being able to take JG and get back, say a 1st and 2 2's, is taking one player and turning him in to at
least 3. From a risk standpoint, I view that as a diversification. No one player is a guaranteed anything in this league - every player's a freak injury away from having their skills seriously diminished.
There's also the risk of not selling at the height of JG's market and ending up taking less for him (including nothing but a compensatory pick). I think this one will be hard for fans - we like the glorious sense of "winning the draft" - it's psychologically hard to accept a price being paid to avoid the potential for a bad scenario that doesn't end up transpiring.
It's interesting to think that, if this season goes according to what the plan seems to be, BB won't trade JG for anything and then Brady will start every game. In that case, BB's shown a little bit of how much he would be willing to give up to ensure a highly stabilized QB position.