When maneuvering, you are watching obstacles and can see how much you need to turn to avoid them. So you give rudder orders. Your actual heading is only a secondary concern.
When navigating, you simply order the desired heading (for minutes, hours, or days). Then you focus on other things while the helmsman sweats the details.
Maintaining a ship's heading is a full time job. If you get distracted, you get off course pretty quickly.
Speed isn't even really handled on the bridge. The engine order (ahead full, back half, emergency stop, etc) goes to the engine room where multiple people do the work.
Note: This is in the context of oil and nuclear steam-powered ships. Gas turbine ships may well have an actual throttle on the bridge. Whether the bridge has a throttle or just an engine order telegraph, the helmsman can often have their hands too full to deal with it. But someone else can do it along with their other duties, as speed control is not so intensive.
I wonder if there is enough information publicly available to compare the workflows on the McCain to the same workflows on the Zumwalt.
Somehow in airplanes a single pilot manages to control not only the rudder, but throttles, ailerons, elevators, flaps and whatnot while also yakking on the radio. And airplanes zip along at 500 knots rather than 20 like a ship.
A ship just can't have as much obstacles as tank negotiating battlefield.
The UK's Warrior armoured personnel carrier is an example of what I guess you mean by 'Infantry Tank'. It has a Commander, Gunner and Driver (plus the 'dismounts' - seven guys in the back who get out to fight on their feet). The driver - as the role name implies - does all the drving. The commander (who is also the loader, incidentally) directs the driver where to go. He does not have duplicate driving controls. If the driver is very inexperienced, the commander will give him very precise direction. If the driver is experienced - in the sense of understanding tactical movement considerations - the commander can be much more hands off.
If the vehicle commander is also a platoon commander, he is also giving orders to the commnanders of the three other vehicles in the platoon. He is much more likely to be paired with an experienced driver so he can focus more on the overall battle than control of his own vehicle.
Larger ship - water is never still, and any vessel's helm left untended results in drift, both in heading and real speed vs ordered. Depending on traffic and the reaction time of the hull, corrections need to be made immediately or even well ahead of time. So helmsman watching constant compass shifts and adjusting steering is a full attention task. As is monitoring speed made vs speed ordered. Still need more eyeballs to keep a full 360 visual watch, radar watch, and a quartermaster to plot position against nav hazards and boundaries and warn against the 'invisible' navigation issues.
If a destroyer could respond to control input like a plane, there would need to be a single person at the helm/throttle.
Entering/leaving any decent sized port that handles larger vessels is a much more intense collision avoidance situation than any airspace management situation I can imagine.
Reducing the reaction space from three to two dimensions and extending the reaction time from control input -> output by a factor of 100 to 1000 is part of it.
The other complication is having a magnitude or more of different classes of "threats", from unexpected solid objects ( chart errors or new items unreported), other vessels both larger and smaller with faster or slower response times of their own, errors in SA... eyes and professional judgment help immensely. Thus the focus on keeping the OOD watching the whole SA.
My sub had at least a dozen people involved in building the "picture" around the boat, visual, sonar, radar... plus two or three of us collating that into displays and reports the OOD could see immediately.
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.
The OOD is estimating a best trajectory given an analysis of the navigation constraints and the behavior of every possible contact in the vicinity. Orders at every level of detail are possible at any time... from 'resume best course for point "X-Ray"' to 'allaheadflankfullrightrudderbraceforimpactport!'. That is the point of resistance to most levels of automation past 'ship's wheel mirrors rudder angle' and 'engine order repeater indicates desired engine rpm'.
The Wolf Rock collision board of inquiry makes for interesting (and embarrassing) reading around what happens when assumptions are being made about who is doing what.
That's how Star Trek do it!