If you don’t mind me asking Tenbones what was written in the sidebar?.
The Colonial Marines book does ABOVE AND BEYOND in detailing the military organizations of the Aliens universe. Not just the Colonial Marines, but the book covers the other major political factions and their militaries as well, including corporate mercenaries. Including differences in weaponry, deployment capacities, general strategies and duties throughout the galaxy, they get deep into the breakdown of the military by branch from the Battalion level down to the Platoon including detailed sub-classes for the Marine role.
It's VERY good. They do a lot of emphasis on the chain of command from the bottom to the top. And that book alone is worth it's price for entry in creating endless military, spec-ops, all-out warfare in the Aliens universe (including ship combat!). You can run campaigns that literally have **nothing** to do with Aliens. You could do Twilight 2000 in spaaaaace if you wanted to.
Then they produce this sidebar telling GM's they shouldn't force their players to worry about Rank (literally after just giving us the whole rundown on chain of command) because some roles naturally are rated as higher rank than others, other players may feel uncomfortable getting orders from higher ranked players. And the PC's should decide as a group how to proceed rather than let rank be an issue.
So sure we're playing an RPG - but for FUUUUUCK'S sake... the whole point of playing a military game is to have some military verisimilitude. You create this awesome book for doing just that and then stick your head in as say "Hey guys! Not really, just ignore this because we don't want you to hurt people's feelings because one person is a sergeant and another is a buck private. Mmm kay?". GTFO with that shit.
It's easy to ignore otherwise. But fuck me... what a dumb sidebar, way to shit in your own bowl of cereal.