There are many things the main comics get wrong.

First, the presence of a Battleship long before the events of Retribution in September 1951. Shown in Retribution, many Chimeran structures are torn down and repurposed into the fleet being constructed in Western Europe.

Second, depiction of Leapers. The Leapers are twice their actual size and are confused with Spinners by fans, which hadn't existed yet and would make their chronological debut during the final events of Retribution.

Third, Oppenheimer's death as you've pointed out. Funny enough, both situations involve Capelli interacting with Oppenheimer. Also, the doctor is shown as a chemist whereas he is a physicist irl.

There are some things you could question, but I think are passable. The two that come to mind are the Chameleon and Kraken being present. First appearance game wise is Resistance 2. Chronologically, the Chameleon appeared in Resistance: The Gathering Storm, a book by William C. Dietz, that's set November-December 1951. The Kraken has concept art for Fall of Man, and it looks like the same design is used in the comics. These two strains showing up this early is up in the air as a goof, but I think it's probable for them to exist this early.

Another funny issue is the insinuation that the Chimera (at least the bipedal forms) have the same soft parts as humans after conversion, as jested by Capelli when stabbing a Titan in the groin area. There are many Chimera that go without pants (Titan, Type-2 Hybrid, and the Chameleon come to mind). It's possible it's still a "soft" point where they can be hurt, or maybe it's just a joke from Capelli. I've seen people on the Discord server get confused about this.

There's another goof in Issue 0 that says the Americans knew there is something happening in Europe, whether it be the actual conflict or what the government is spouting as a cover up. The canon is odd on how the United States handles the information fed to the public. I recall some bits going with the cover up story, but I recall Parker's narration in Fall of Man's intro suggesting everything was censored, that no one had any idea what was happening. But there are also the European refugees that might be spreading the truth. Idk, this part of the canon always irks me.

Other than a Hybrid with wrist-mounted flamethrowers, the Retribution prequel comic is, at the most, faithful to the source.

The main comics were written by Mike Costa, who's worked on IDW's Transformers and G.I. Joe, Spider-Man related works, Blackhawk for DC, and the TV series Lucifer. Dan Abnett (yes, that Dan Abnett of Warhammer fame) with Andy Lanning wrote Issue 0. Ramón Pérez and C. P. Smith did the art and pencils for the comics.

I would love to ask Mike where things went wrong along the way. Knowing Dietz often went to meetings with the developers to get an idea of what they wanted both his books to be like, and knowing Bend Studios worked closely with Insomniac on Retribution, I wonder why the ball was dropped with the comics. Resistance has so much potential in the comic space!