By my count, renouncing Zeller, Olynyk, and Young right now would put the C's at 25.5m cap space (based on the 99m cap number). That includes Zizic, Yabu, and Tatum's cap holds. That leaves them 4.2m short of a max offer. Assuming the tweet above is the plan, they'd need to first free up that space, then have a salary matching trade for George. You probably need to save AB+Crowder for the trade part so that salaries can match, so how do you free up 4.2m without moving either of them? Dumping Mickey, DJackson, and stashing Yabu gets you to 28.1, which is still 1.8m short. I don't see an easy path to freeing up the salary space for a max offer, that still leaves tradeable salaries to get PG, unless one of Smart/Brown/Tatum is getting moved.
What this tells me is that Brown or Tatum almost certainly would have to be one of the pieces going to IND, just to make the salaries work. That way, you could move Crowder now for a future pick, then have a deal based around AB+Brown+(say, Mickey, for salary matching). That would put you just over cap, ~101m, with a 10-man roster of:
Smart/DJackson
IT/Rozier
Hayward/Tatum
George/Yabu
Horford/Zizic
That's a WAY shorter bench than they've seemed to preferred, and they'd be over cap, making it very hard to add any other meaningful pieces. But it is a nice starting 5.