That layout idea does require a sectorplate, so I fancied having a shot at making one. A simple structure from 6 mm ply forms the base, the moving part is similarly formed with deep sides to create a U section.

The pivot is a bearing which came from a scrap photocopier. Seems to act well as a thrust bearing.

At the other end a bracket holds a pair of ball bearings which run on a hard plastic surface, Very low friction.

A load test with some old lead-acid batteries. Much more weight than it will have to carry in practice, but it still takes only a small force to move it.

The sectorplate has a capacity of a loco and 4 or 5 wagons. Probably sufficient for a small shunting layout.

A reasonable start. Now to start paying with some control mechanisms on the bench. Inexpensively of course.