Space Marine Cheese?

Yup, that's correct. That also means that you have additional deployment options, too. If you deploy first/go first, you can spread out in a much larger area as an alternative to castling. Both accomplish the same thing, making it difficult for him to hit multiple targets with single templates.

I want to add that per the recent (and now official) FAQ you measure from the outspread tips of the pods.

Which is a ridiculous boon to their ability to claim objectives but also means that when castling you can leave pretty massive holes that he can't land in.

Unless of course he decides to glue all of his doors shut in which case, gratzi for keeping him from having a 12 inch bubble of obsec.

Now if he tries to say "I'm not opening them this game but I am opening them when I want to grab an objective". Politely direct his gaze to the FAQ, or anywhere else and stab him in the kidneys while he's distracted... I'm kidding... mostly...