At this point in the top down process I am focusing on the wheel/rail interface; I don't care now about the detail of spokes, hubs, bearings and axles.

I created a rail track part by sweeping the closed sketch profiles of a mirrored pair of rails, and this will be fixed into the top assembly.

I created a wheelset part by revolving the closed sketch profiles of a mirrored pair of wheel rims. I want to assemble two of these into a flexible bogie sub assembly which can be towed around the track by a linear motor.

I have already tried assembling the wheelset parts with layout lines on a plane with the idea of defining the bogie from mainly layout lines and a notional tow point, and so the questions:-

Are layout lines and points, including origins, centroids and centrelines, "components" which can be fixed and locked in a flexible sub assembly?

Can flexible sub assemblies be mated to each other at layout points?

The Mates documentation talks about lines, points and planes, but I don't know whether layouts are valid in this context, and I don't want to spend time attempting something which is impossible.