Tolliver is Anthony Randolph insurance. Chuck Hayes is in the top four of the big man rotation. (What don't you like about him as a backup center? He's undersized, but he's putting up good numbers and is excellent on defense.) For the record, though, Tolliver absolutely is an above-average defender.
Also, you're massively underrating Rush's defense. Take a look (after you expand the pick to readable levels):
Rush's defense is pretty much in the elite category. Defensive statistical metrics are flawed, but when a guy is shutting down his opponent in just about defensive set, it says a lot about the guy.
As for Jones, here's an article on how Jones still remains a good defender, despite the loss of some athleticism:
Link.
I do appreciate the Hollinger quote, though, which was apparently to prior to this season. Hollinger's suggestion that Jones can't be a rotation player seems kind of silly now, doesn't it, since Jones has been a rotation player for the Heat all year, and has performed well in that role. Also, Hollinger's "projected stats" aren't even close for Jones.