I watched the Cruel Sea the other day. My dad served on a Flower class Corvette and says the conditions below were very well done in the film including the galley with hot meals often spilling over the galley sole. He also remembers taking slops up from the galley to put over the side on a V&W class destroyer mid Atlantic which was equally hazardous.
Your suggestion of moving the galley aft is absolutely correct but moving the heads forward might give problems only solvable by engineers from the International Space Station. Heads port, galley Starboard?