The OOD and the 2 senior EMs move to the 3 empty billets in the control room. The two EMs are the missing planesmen!

Move them to the control room and you will see them there, manning the planes. The 2 junior EMs go to Hogans' Alley, where they are available for relief if needed - to free up a PO for the damage control party, for example. EVERYBODY must clear the deck or they will be burgered if you are depth charged. As far as SH4 is concerned, anyone assigned to topside duty is outside the hull, whether they are on or off watch. BTW, by extension of this "logic", off-duty topsiders are vulnerable to injury if you are bombed or fired upon while surfaced.
Thanks, UberSoft. Splendid job!