Liquid core?

That's a fair point. Being a botanist rather than a geophycist does not impede my willingness to speculate ....

A model

Imagine a rotating semisolid ferrous mass. The rotation is a vector (constant magnitude and direction). The core flows with respect to the velocity and direction of the rotation. This is the origin of the magnetic flux about the Earth.

Liquid core in rotation will establish channels of flow. The flow channels are equivalent to a dynamo (a coil of solid wires oriented to a magnet).

To balance that force vector one would seek equal and opposite vectors oriented with respect to rotation direction and velocity)