Current effect
One's mind keeps returning to how wind and current would affect the parts found so far apart.
Given that the recorders appear to have been dislodged at impact and that they are amongst the densest parts, one would surmise that they sank very near the actual point of impact. Downstream drifting of the rudder and fin is not surprising given their residual buoyancy and I shouldn't be surprised if the elevators wash up on a beach, with or without the apu, near where the nose cone was found.
What I do find surprising, though, is that the recorders were both found "under a wing" which, if the premise of their sinking first is correct, would indicate that part of the wing and main fuselage also sank very rapidly. Perhaps, if still attached to the wing box, dragged down by the weight of the main undercarriage?
The puzzling thing is the cockpit/forward fuselage. Little buoyancy, weighted down by the nose gear and electronic bays, would it not also sink like a stone? And, if so, one'd expect it to be near the main fuselage. I wonder if it's not folded underneath.