Alexander, McCullough, Christmas, Mickey (better defender) all seem like a Brandon Bass replacement. Some might be better at defense, or shooting, or post moves, ore rebounding but they all fit that rotational player role he played so well.
I think Mickey could be the biggest gamble but Christmas could be a solid backup as well, especially since he has an inch on the first two guys.
Also, I like Dakari Johnson as a backup. He'd be the complete opposite of Zeller. We could also trade that 2nd rounder and sigh Biyombo.