All that said, I would not do the trade if it included Rob. Replacing Horford with Sabonis is the point — failing that, we shouldn’t get involved.
I 100% agree with this. I'm not sold on Williams and Sabonis together (or Tatum and Sabonis together), but I'm out when the deal moves to including Rob.
Then you almost certainly don't upgrade talent to Sabonis
And I'm fine with that. I want to keep RW III.
You're assuming Sabonis is a talent upgrade. I can understand why -- I just don't see it that way.
There's also the other dimension to all this - the fact that Rob Williams is a walking injury and has so far averaged 38 games per season over the past three seasons. Sabonis has averaged almost double that at 66 games over the past three seasons.
Doesn't matter how good your player is if you can't depend on them to be suited up when the playoffs come around. Just ask the Lakers (AD) and Clippers (CP3+Griffin).
I like Rob Williams a LOT. If we could confidently depend on him to give us at least around 65 games per season and be suited up when we need him most in the playoffs, then I could understand the argument. But a Sabonis on the court in a Celtics jeresey is far more helpful then a Rob Williams sitting at the end of the bench in a suit twirling a towel.