Perhaps this is just an echo, but I don't see this being an effective strategy for Cleveland. If anything, this will make Boston's offense more potent because:
1. LeBron can definitely prevent Rondo from getting his little floaters and lay-ups off in the paint, but LeBron can't stop Rondo from dribbling wherever he wants to. Rondo is too fast. If LeBron tries to muscle him, he'll get called for fouls (nearly) every time.
2. Meanwhile, when Rondo gets to his spots (which he will), he'll have MORE passing options because LeBron will be guarding him and NOT Pierce.
3. I don't care if LeBron is the greatest physical specimen on the planet. I don't care if he's on PEDs to enhance his body to an even greater level (FWIW, I don't believe he is using PEDs). Rondo can (and should) run around enough that even LeBron is bound to get worn down by the 4th quarter. Having a tired (perhaps only slightly compared to normal) LeBron is bound to produce positive effects for the Celtics at the end of the game.
4. This is a risky strategy because if Cleveland spends a bunch of time preparing for LeBron on Rondo, then that's time they won't be spending coming up with another game plan. As soon as the LeBron on Rondo plan implodes, they'll be left scrambling for adjustments and by then it could be too late.