RealGM

Per Q84 of the FAQ,

if a team used an exception to acquire a player (which means it acquired the player by any means other than using cap room), it cannot include that player in an aggregated trade for two months.

Houston seems to have been capped out in the season just ending. So these guys they just acquired and flipped weren't acquired into cap room. So how could they aggregate and flip them?

HOU was a bit under the cap. Those players when acquired were able to be added to their roster using cap space.