I'm not advocating full autopilot; I agree that safe trajectories can be harder to plan in dense 2d than in sparse 3d, and that military ships in particular often have high-level objectives that would be extremely difficult to formalize for input into a planner.
Rather, I'm doubting that going in a straight line at a target speed is correctly handled with a three-person steering wheel. My understanding is that the current OOD already has a trajectory planned through the workspace coordinate system (space, time) and gives orders in workspace coordinates ("go this fast") that are then translated into low-level control outputs ("set the rudder to X"). It sounds like in some cases the OOD even gives direct control outputs - "Prepare for X thrust in Y minutes". Certainly these low-level controllers can't be a good thing for the OOD to be spending cognitive resources on, and I'd be astounded if we can't replace that with a computer that translates directly from that trajectory to the control outputs.
That's why I used airplanes as my example, rather than, say, autonomous vehicles. A commercial airliner's path through the air to a safe landing is basically hard-coded. The task of the airplane's autopilot, then, is simply to follow that trajectory - and I'd guess that it's far more difficult for an airliner to follow a workspace trajectory than it is for a ship to do so.
Really, the hard part is going to be getting the trajectory out of the OOD's head. And even then, it'd be so much easier if the helmsman could execute "go this way" by punching "this way" into a computer instead of staring at a compass and directly and continuously controlling the rudder.