IIRC, we have John Eaves to thank for selecting the ships on display. It was a great bit of continuity porn, referencing VOY: "One Small Step", ST: FC, ENT: "First Flight" etc. I'd love to see the pictures in Marcus' office. One high up on the wall of the Golden Gate bridge looks suspiciously similar to the cover of Shatner's novel Star Trek Academy: Collision Course. There's also what looks like a space map similar to the Star Trek Star Charts posters, with coloured blobs showing the different powers and territories. Or maybe it's just coloured blobby space art.
I'll have to go back and watch again King. Having just finished watching ENT I started Star Trek 2009 and Into Darkness and loved the ENT references, started drooling over the ships and never noticed anything else!
I always thought it funny that he had a model of the new secret battleship he was building sitting right there on his desk for all to see. Didn't anyone ever say "hey, that's not a ship starfleet has ever had"
It's not as if the ship would actually have been declared "secret" by the heroes or the villains. Her existence surprised Kirk and Scotty, and some of her capabilities took Kirk by surprise, but 98% of Starfleet might have known all about her, not having been out at Nibiru or wherever when the memo was circulated. If Marcus wanted to ignite his war there and then, it's rather likely he had more than one example of this battlewagon available - after all, he was intent on sacrificing the Enterprise as a trigger for the war, despite that vessel being the second-largest design witnessed on screen. There'd have to be quantity to back him up if quality mattered so little to him. Timo Saloniemi
Marcus uses it as plausible deniability. When reporters storm in asking about a rumoured black super deathship, he can point to his desk and say "It's just a model, son! I have a hobby. Now get the hell out of here!"
Having a Vengeance model on his desk was rather silly, especially having Marcus stop and stare at it for twenty seconds. But I guess anyone visiting his office who wasn't on the Section 31 payroll would likely just look at it and think "maybe it's on the drawing boards as the next starship class after the Constitution class" and not think any further on the matter.