If you control the situation around Romo, you could win it all with Romo.
The defense would need to be sharp enough to keep the game within control. Not just close enough to win at the end. But the momentum of the game has to be such that Romo doesn't believe he alone has to carry the team.
That is a fine distinction, and one that might be lost one some. I am certain others will want to write a book with stats on why that may not be the case.
However, I believe that Romo feeds off the circumstance and his results tend to either elevate, or diminish depending on how dire those circumstances are.
I'd like to see him with a crisp running game that can control the clock and keep the ball out of his hands in situations where he thinks he has to carry the team.
I think of the Super Bowl Aikman led against the Bills where the real danger was past by half time. The first Bill's Super Bowl in 1992.
If the defense can feed a lead to Romo and control the other team's offense, then I believe Romo can take this team to the top.
But if the team needs a drive to win it all, or a quarter where he has to keep coming back to tie or gain a lead, I am not certain he has that mental toughness to grind that out.
There is a huge difference between being tough physically, and having the mental discipline to control your panic and lead men to success.
I could be wrong. But history suggests this is becoming more and more likely as Romo's career moves toward the day he hangs them up.