Taking a look at the various sign-and-trade options for Jimmy Butler and the Houston Rockets
Regarding how Houston can acquire Jimmy, it's relatively simple. It can happen in one of two ways:
1. Philly maintains cap holds on their free agents, which would create a scenario where trading Butler only counts as $20 million in outgoing salary for the 76ers but $32 million in incoming salary for Houston. As a result, Houston would need to re-route Capela to a 3rd team while Philly gets Eric Gordon.
2. Philly renounces their cap holds (with the exception of Tobias Harris), allowing them to sign Butler with cap space. Then they can trade his $32 million to Houston, probably still re-route Capela to a 3rd team since they have Embiid already, and result in Philly having roughly $25 million in cap space to sign free agents and then re-sign Tobias after the fact. In this scenario, Houston would have 7 roster spots to fill with roughly $13 million below the tax apron. This would likely result in 6 league minimum contracts and one $3 million contract for Houston.