With all due respect to the not-samurai critique, if you read the graphic novel upon which the novel AvP: Prey is based, you'll see that a lot of what we did in the book was to novelize the comics. So the credit for much of the plot and action goes elsewhere, and I do believe I've mentioned that a time or twelve.
My daughter and I added our bits, but we didn't create the AvP concept -- talk to Chris, Randy, and Mike about that. We followed their lead.
You need to at least have read the book you are criticizing or you'll come across as an idiot. If you read War, you should have been able to look down there under the title and see the name of writer, and it's obviously not my name.
As for the culture we did create, since it a) didn't exist before and b) is in a completely fictional universe, then it can't really be "wrong." You might not like the direction in which we took it, and that's your right, but we did take it there, and since that's why they hired us.
That a culture like the Preds would have things in common with samurai doesn't strike me as the least bit unlikely, given the set-up from the original movie and subsequent expanded universe material. This was written and produced for an audiences of humans who primarily speak English. That's where you start.
I expect, having done a bit of research on samurai culture, written a book based on that outside the Aliens and Predator universe, and having been in martial arts for more than forty years, I know as much about that culture as somebody who can't spell "samurai" correctly.