None of the past championship teams were above the cap.

Rockets, Bulls, Lakers, Spurs, Pistons, and Heat, in this not so short time spam, they were all below or barely over the salary cap. On the other hand, super rich owners who do not hesitate to throw money into the team, like Knicks, Mavs, Blazers, etc etc, so far, haven't been able to buy a ring.

Les is no Allen, but he's not cheap owner as Atlanta. Rockets salary is in the upper half or 1/3 among the league, but their performance isn't.