Is it unreasonable to assume the following averages when Rondo gets back?
Rondo: 14
Bradley: 14
Green: 16
Sully: 16
Asik: 10
Crawford: 10
Olynyk: 8
Pressey/Fav/Hump/Wallace combine for around 10
Those are pretty reasonable numbers and that's 98 points. Not a ton but enough to win games, especially with an elite defense.
This is a good way of looking at things. In most years the average team gets about 65 ppg from its starters and only a handful get over 70 ppg from their starters. While it's unclear what happens with Rondo's health this year, it's not a stretch to see Rondo/AB/Green/Sully combining for 60 points or so, especially next year. You wouldn't need a ton of scoring from Asik. As for the bench, we're a little weak there after trading Bass and Lee but Crawford, a decent scoring wing and a backup big or two should supply the scoring we need.
Combine that with the defense we should see and it's a fairly solid unit. Again, probably a player away from being at least a fringe contender. It's true the team doesn't have a top level scorer, but they do have Rondo. His ability to create open looks for his teammates is a big help in the playoffs, when defenses are tougher.