I don't see how benching Ray fixes anything, considering you aren't going to cut his minutes (and if you do, well that certainly won't help the offense). So now Pierce is the only real scorer in the starting lineup?
Personally, I'd do 2 things. First, I'd give the starting 5 some more rope. They've played 4 games together and guess what, we're 3-1 in those games, and +26 in scoring differential. We had 1 stinker in Indiana where Pierce was ice cold. It happens.
But let's suppose the offense "continues" to be a problem. I say start Bass at center. Why?
1) He's our 3rd best scorer after Ray and Pierce. On some nights he'll be our 2nd or even 1st option.
2) He's only playing 27 MPG. Want more offense? Play him 35 MPG like Rondo and Ray. God knows O'Neal could use the rest. Dude is putting up something like 17/8 with that kind of playing time!
3) He'll be much harder to defend for opposing 5s than O'Neal, especially in the running game.
4) O'Neal can be our 1st big off the bench, since Garnett & Bass can both play the 4. Make the 2nd unit truly a defensive squad -- yeah they may have trouble scoring, but I'd rather have dangerous starting 5 with a hustle / defense 2nd unit, then 2 units that both struggle to score. Bradley / Dooling / Daniels / Pietrus / O'Neal / Stiemsma can all get after it on defense.
5) Stop swapping units wholesale -- leave at least one shooter (Ray, Pierce, Bass) in with the 2nd unit. Run lots of plays for that guy and let everyone else go nuts with pressure defense. For example, sub Pierce for Pietrus earlier in the game. Then bring him back to FINISH the quarter with the 2nd unit. He'll be the leader on the floor and can create his own shots. I think Pierce would relish the role - start the game, get his minutes, and LEAD the 2nd unit for short periods as well. Also, Pierce is our best player at drawing fouls. Why not play him at the end of quarters when teams are over the limit?

6) Encourage Garnett to focus even more on rebounding & defense -- he doesn't need to score as much with Bass on the floor, and frankly he's "only" the 4th or 5th best scorer on the team these days.
Now of course there is a downside to Bass defending the 5 for long stretches, but we already know we need him on the floor for most of the game, why not find the best way to play our best players?