It depends on what the cap is...
Bulls have 22 mil committed... What's the cap set at? 54? That would give them 32 mil in cap room... enough to perfectly offer two max contracts if they sign another team's player. Bosh gets 16 mil... Johnson gets 16 mil... then they trade Deng, James Johnson and Taj Gibson to Cleveland for LeBron with a starting salary of 17.2 million (James gets extra cash from the sign-and-trade by signing with his own team)
Obviously this would all be worked out in advance... James would commit first, but that's how they would work it out.
Cleveland won't allow Bron the S&T option. Right now being able to offer the most money is their only leverage.
... they are lying. Like you said... that's their only leverage. On July 1st when Bron comes to them and says, "hey... either I'm signing with the Bulls for 16 mil... or you can have Luol Deng and give me 17.2 mil", do you really think they'll say no?
Deng is 25 and averages 17 points and 7 while playing solid defense. He's signed for 4 years with a starting salary of 11.5 million. Is that really a bad contract?
In what scenario is a market like Atlanta, Cleveland or Toronto going to land a player like Deng for a contract starting at 11.5 million? What are they holding out for... Kevin Durant? Come on...