I think if the Cs can get both Hayward and George, they'll move forward with contingencies.
This year, we are ok with IT on a cheap contract
Next year, if IT performed at the same level, we re-sign him and pay a heavy tax ($75M). If not, either he walks ($50M overall difference and possibly under the tax) or signs for say $20M ($25M difference).
Two years out, if we're contenders and IT re-signed, we probably pay the tax and pass on paying Smart.
Three years out, Horford is off the books and we get under the tax for 2 years to avoid repeater status.
Something like that. Ainge and Wyc are smart- I think they'll take a window of contention if they can get it, knowing it's max two heavy tax years. Cleveland paid $50M+ for 2015-16 when the cap was $84M, so $75M is going to be near the high end but no unheard of. GS paid $20M and that's going to go much higher to keep the team together.