magnetic motor (with electromagnets) idea

[vineet_kiran]

The magnetic drag from the soft iron makes this an extremely inefficient design.

That is not a problem at all. You just have to provide some force on the other side of magnets to balance the force of attraction between magbets acting on one side of the bearing.  There are other easier methods to do it than providing soft iron as shown in  the diagram and people who are 'fit' to conduct experiments would have already solved that problem.

The question here is whether the smaller magnet rotates the bigger magnet with equal speed (RPM).  It definitely does,  provided number of poles on both magnets are equal  and ratio of diameters is not too high.