Saw in your summary that you said for The Fall of the Governor, the Governor's the primary antagonist, that's not true. The story follows his perspective thus making him the protagonist of the novel, and Rick's group being the antagonists.
The story follows the Governor's perspective, correct, but mostly through Lilly Caul. The Governor was followed mostly in the first part and while is most certainly a main character, isn't the protagonist. We constantly see all the anatgonistic stuff he does through his perspective and that builds up until Lilly ultimately sees him for the monster he is in the ending. Its important the novel follows Brian to see the evil things he does so that Lilly can gain his trust up until that final part.
This brings me onto Rick being the antagonist. He is an antagonist, however just because he is the leader of the prison survivors doesn't mean he is the primary one (that might not be what you were saying but it sort of sounded like it to me). After the Governor, I think Michonne would be secondary because she has done the most to get in the way of the main characters (torturing the Governor, shooting at Lilly and the others etc) which is a lot more than Rick has ever done which is nothing except escape (we see him arrive at Woodbury, then he sits in the infirmary with Stevens until he escapes without hurting anyone, and then he escapes at the end with Carl), Michonne is definately more antagonistic than him and if the Governor isn't the primary one, she most certaintly is.