The thing is....
They're not really going to know it's solid until they see him play under 100% full-out game conditions. So, using your rubric, they would have to keep everything status quo until after week one, unless the answer is clearly in the negative or they get a monster (who shows it from the very beginning) in the draft. Like I said, your way is just as complicated. There's no simple solution here.
Actually there is a lot they can do to help determine where Vince is health-wise AND athletically. There are lots of drills and exercises they can do to find out if he can still play without having to actually get on the field in a regular season game.
I'm sure the Pats have all of Vince's strength, flexibility, and quickness metrics from every season. It won't be a mystery to see if he's slipped, assuming he's healthy enough to participate in the drills.
While you may be right that this is a complicated situation. But that's only because of Vince's long and fruitful connection with the ownership, team and fans. As a simple football decision, I think its pretty simple.
You have an older player, who seemed to have visibly slipped in the few games he played before he was hurt. He is recovering from an injury that few players return from at the same level of play. He also carries the 3rd highest cap number on the team.....and you need cap space. C'mon DI, at this point in time there hasn't been a SINGLE report of what Vince's condition is, nor any speculation about when he will be able to participate in a practice.
Vince is a rarity in that after he got paid top dollar, he earned those dollars....until last season. As a long time Pats fan, I really, really, want Vince to stay. However, as a long time Pats fan, I'll be damned if I'm going to be held emotionally hostage while Vince has a hissy fit because reality has hit home.
The team not only needs to create some significant cap room before the draft, it is highly unlikely that Vince will have the ability to play to the level that would warrant him having an $11MM cap number....or even half that.
Right now Vince wants everyone to think that he's the injured party here, when he's clearly not. He's the one who is holding up the show here. When is Vince going to tell us when he'll be ready to play. At this point I'd accept an "indication" of when. In fact, as this drags on, this whole issue becomes less and less complicated.