There are two possible problems: I don't know which one you're worried about.
PvP is totally avoidable. We did _Council of Thieves_ with a party in the same neutral/evil neighborhood that could work for _Hell's Vengeance_. The PCs had strong ties to each other and were smart folks who understood that backstabbing loses allies.
The problem that has killed a few evil campaigns locally is that if you do well-fleshed out, vivid characters who actually respond to the events, a game with too many vile deeds can turn out not to be any fun. We did a Shadowrun game where the PCs were Insect Totem cultists--four sessions, and I for one was tired of doing awful things well before the end.
The Black Company is a great paradigm for having characters you can care about and root for, despite the fact that they are working for the Big Bad (and they know it from quite early on). I'd also mention Glen Cook's short story "Filed Teeth"--my husband ran an adaptation of that story which worked beautifully. It had the "swear a pact" aspect of _Vengeance_: half the PCs did and half did not, and it made for a lot of unease amongst them. There were many late-night discussions of whether our employer ought to be offed, whether we *could*, what would happen with the pact-bound PCs.... In the end we never did turn on him.
I have not read _Vengeance_ but my GM read it and will not be running it; he felt that smart, ambitious evil characters would balk at the plot and this would be hard to fix. The word "thugs" came up a lot in his review. I'm not overly interested in being a thug.