Simple, Roy wasn't a member of the New Teen Titans, neither was Garth/Aqualad. Roy wasn't even a full time hero at this point, he spent a lot of time working as a DEA agent/consultant. He showed up from time to time, and helped a time or two, but he wasn't a regular.
He seemed to get more involved in the shady ops side of things, until eventually he moved in and took over the Titans when he more or less forced the team to align with the Government and Dick left in disgust. Yup, Roy was "a suit" for "the Man", Oliver must have been SO proud.