If you are so spoilerphobic that an extremely vague explanation of why you don’t need to worry about the comic book spoiling the show a lot any more because it is quickly becoming impossible, and also why they must be fundamentally different by definition, you should skip this whole thing, and I apologize for the interruption, and I won’t talk about it any more, but this is why I think that nobody should really be worried about the book spoiling the show at this point.
Unless you’re planning on reading the comics, I think we’re getting well out of spoiler territory, so phobics can hopefully relax a little. They’re quickly approaching the point True Blood is at, where knowing the source material is little more than an entertaining aside to see how things are different that in no way informs future events in the series (True Blood example: Jason IS a werepanther in the books, but he specifically is not in the show). I think that there are maybe a few key scenes they’ll be replicating (one I’ve already noted, plus the end of the second hardcover, which I think is the close of issue 24, just because the framing on that shot begs for it to exist, and some stuff I haven’t read yet because my hardcovers are currently lent out as I struggle to process all my media that I think they set up with the tool kit in the very first episode this season and I believe it’s been roundly “spoiled” on any number of covers, though I could be wrong), but let’s be clear. Optimistically, this show will run for six or seven seasons. Pessimistically, three. It’s going to need to end, and the writing staff is going to want to end on a satisfying note. That right there guarantees you that the comic book doesn’t spoil the actual show. Rather than getting closer to the comic book (which is unapologetically an ongoing story that’s already got more years in it than the television show will ever have and Kirkman has said he’s got no plans to conclude any time soon), it’s only going to diverge further at this point. It has to if it’s going to be good television.
It’s different for something like Game of Thrones. Game of Thrones is trying to ape the book series, which itself has a definite ending. Somewhere in his mind, Martin knows how the story all turns out. The show won’t be deviating in any significant way from that plan. You CAN spoil that show from the books if what they’ve done with it to date is any indication. I’ll assure you that the same is not the case for The Walking Dead, which has already deviated from its source material in significant ways that crucially inform the plot and will necessarily have to continue to do so by virtue of the fact that this show will end.
explanation, which I guess I’ll tag, though I’m explaining why I don’t think it will really spoil anything
As for The Governor, he’s an antagonist, but the fact that Kirkman wrote and published an entire prose book a little over a month ago about him leads me to believe that he won’t show up at all under any of the names we would recognize, though perhaps elements of his character will show up in an antagonist in a later season. Even if he did show up, certain aspects of the character simply won’t fly, even on AMC - specifically, all that raping.