Most shows these days have a lot more producers than that. In the writing staff alone, you've got several tiers of writer-producers: executive producer, co-executive producer, supervising producer, producer, co-producer, story editor. Then you've got the various executive producers who run the production company/ies making the show or who are on board as financial partners. Then you've got the executive producer, line producers, associate producers, and unit production managers who handle the actual physical and logistical process of turning the scripts into episodes -- the budgeting, casting, design, building, filming, post-production, etc. Often you have separate producers specifically for the visual effects company/ies. Then there are consulting producers or executive consultants, which are usually former creators or producers who've moved on from the show but are kept in the loop in an advisory capacity, or just veterans who get paid to advise the production staff.
So at this point, only the bare bones of the show's staff has been assembled. Kurtzman and Kadin are the executives in charge of the production company making the show. Roddenberry and Trevor Roth are also production partners on an executive level. Fuller is the co-creator and showrunner. Meyer is listed as a consulting producer -- which means he's less directly involved in the process than I thought, serving more as a senior advisor to Fuller rather than someone who'll be in the writers' room day to day. That actually makes a lot more sense, given that he has so little TV-producing experience.
So that means I was wrong when I said above that they didn't have room for any more top-level writing executives. We only have one real writing-staff member announced so far, the showrunner, meaning there are at least a half-dozen openings there (all the writing staff producer tiers I listed above plus staff writer, and maybe a second EP to be Fuller's second-in-command). And aside from Heather Kadin, nobody on the logistics side of the production has been announced yet, nobody who'll be responsible for the physical process of making the show.
As for MacFarlane, it seems to me that he's too senior a production executive at this point to be able to contribute hands-on to a single show. He's more on the level of Kurtzman or Abrams or Greg Berlanti, the executive of a production company that has a lot of different irons in the fire at once. The show already has an executive on that level in Kurtzman, and perhaps in Roddenberry as well. More execs on that level just means more notes being handed down to the writing staff, and that just clutters the process. What it needs are more staffers who'll actually be there in the writers' room, who'll be players on the team rather than senior management.
