For this photo they had the troops muster on their particular top deck ~~ way too much weather mid-ocean. Everybody was safely stowed below deck during the crossing ~~ but not sure what the arrangements were. You’re probly right tho ~~ high-ranking ofcs had access to the “promenade deck” topside but not the grunts.You know what I see in that photo? Enlisted on the bottom three decks (there's an edge of another deck in the pic) NCOs on the fourth deck, junior and field grade officers on the fifth deck and brass on the top deck. Once you've served and seen it you can't unsee it.
Crazy high ladder climb.