Which part of that quote do you think is a misreading? That's exactly how I remember it unfolding in the book.

All of human history is manipulated by the Tralfamadorians to get a single piece of metal to Titan to repair the Tralfamadorian spaceship. The army officers, you, me, everybody, we are all the result of Tralfamadore's plan.

Right, but I don't see anything in the quoted text implying that's not the case:

> In Sirens of Titan, there’s this army of Mars which is really a joke. No one in the army, [not] even the officers, are really in charge of what’s going on. They’re all mind controlled. Nobody has any real free will. They’re just set up as a pawn to be sacrificed, to make Earth come together, kind of Watchmen-style.

Because either the person quoted or the article itself wants to highlight an apparent contradiction between making a wargame and writing the novel. If the point is that war is meaningless, then maybe there's a contradiction, but if the point is that everything is meaningless, then there isn't any more of a contradiction than eating breakfast is a contradiction.