use this base: the bridge, from "floor" to "ceiling" means one deck. offset the rest of the lines by the same distance, and you get the inner layout.
take as "one deck" a distance in the silhouette that you know is one whole deck (usually, the bridge). the rest is just copy-paste.
if you see that you don't fill a specific distance with an integer amount of decks, you have two ways: stretch the existing divisions to fill the gap, or add one more deck, shrink the group, and make the decks shorter.
a complete deck is (maybe. in real-world assumptions.) at most 3,5 or 4 meters high. say, 2.8 meters of usable space, and the rest for service conduits, either above or below the deck.