Cannibals come in dead last. Other than themselves, necrophiliacs are the only ones on the list that are in any danger from these guys at all. And I imagine that generally speaking, a lot of cannibals might even shy away from eating the necros because really, who wants to eat a guy who's been putting it in a bunch of corpses? Kind of dirty and nasty if you think about it. Even if you clean him up real good, it's just hard for most to get past the mental image.
Bruce Campbell comes in next. While neither the cannibals nor the necrophiliacs pose any threats to him, because he's, well, Bruce Campbell, no matter how witty/clever/cute/badass he can be, there's a population explosion at hand on the planet. This means that no matter how many cannibals or necrophiliacs he kills, they'll soon be back as zombies. Likewise with all that are daily reborn as undead, dying from other causes such as old age, congestive heart failure, cheesy-poof overdose, sheer embarassment, and laughing themselves to death at the irony of it all. For him it would be a lifelong and uphill battle all the way. The only sense in which Brucey Baby wins is in his own mind, provided he passionately and undyingly loves nothing more in this world than endless slaughter.
Zombies are next. They simply give zero fucks about anything but chewing up the living and endlessly scarfing down brains. They might be the winners, but for the fact that they just don't care. You can't "win" if you don't care about winning. It's just another day of shuffling and brain-disposing. Every day the same - perhaps until all the living are now gone past dead to commence their own shuffle/brains/rinse/repeat rut. How confusing and boring will that be? Your sole raison d'etre, denied. At that point, maybe the zombies themselves will be coerced into cannibalism, just for something to do. It would get into a gray area here. Would this be the zombies being the last contenders standing, or would they now be considered cannibals? Perhaps the true winners of this fight would be zombie-cannibals. And when it comes down to the last two, the winner of that eat-off will be a super lonely, hungry, undead dude, with no particular place to go.
I suppose necrophiliacs would come out on top, because they would have available to their sexual desire all the freshly dead, plus all the hordes of zombies. I suppose getting frisky with a zombie would be sort of a challenge round for an unseasoned necro. The bedding-down of the undead would probably be a matter of widely varied taste amongst the necrophiliacs. Some, I assume, are necrophiliacs in large part due to the fact that their partners are very inert, making the wriggling zombies unsavory to their sexual palate. Conversely, there may be those necros that are in it simply for the aspect of death, which might make the dead-yet-lively zombies extra-arousing compared to the lifeless fucks they are used to encountering. Most speculation aside, necrophiliacs would have a veritable smorgasbord and buffet of dead with which to off their rocks. And even when they are victimized by one from an opposing faction and come back as zombies themselves, as long as some other zombie hadn't already chewed off their dead-loving parts, they could still indulge in their no-pulse debauchery, making it a win-win-win situation for these guys.