Henners91 wrote:It occurred to me that the reason that the SM have the "best" and most sacred vehicless is because of their high value; obviously rare and artisan-crafted machines are given to the Imperium's finest before the guard.
Not entirely true.
It fits for the Land Raider... but the Rhino is described in the background as the most ubiquitous (which is appalling grammar, but you get what I mean...

) vehicle the Imperium owns.
But surely forgeworlds that can make such vehicles would also hold them for their own use?
It would really depend on resources, and on how many and how fast they can build. If production can only keep up with the needs of the Marine Chapters, then they would get priority... ideally, anyway. That's not to say that some Forgeworlds wouldn't keep some anyway, whether they're supposed to do so or not.