Your recollection seems pretty spot on when compared to a 1920 plan of the yard, though your Plumbers Shop is actually marked as the Pipe Fitters Shop and Boiler Tubing Plant. The main Plumbers Shop in those days was the other side of the Boiler Shop at the west end of the Engine Shop range.
In the photo the building immediately to the right of the Joiners Shop was the old Drawing and General Offices. South of the Mould Loft, partly hidden by the smoke, were the Ship Fitters Shop and Smithies, whilst in the immediate foreground is the basin in which a large Floating Dock was built for the Admiralty in 1912, with alongside it the Heavy Plate Shop.
And, just in case anybody is wondering, the large vessel under construction on No 6 Slip at right is the Cunard liner Samaria which was launched on 27th November 1920.