Personally, I think the FE theory goes further in explaining the magnetic poles of earth.
The RE theory states that the earth has a molten iron core that is spinning at a constant rate, which is what generates the magnetic fields. But wouldn't the core slow down over time, due to friction? If we consider the middle of a round earth to be a closed system in which energy can neither penetrate nor escape (ignoring for the time being geothermal energy, of course) then the friction would gradually slow the rotation speed of the earth's core, gradually weakening the magnetic poles. This is not the case. Clearly, energy is being applied to this system to offset the losses due to friction, which is impossible in a RE world.
We know that gravity is 9.8 m/s^2, and FE theory attributes this to energy being applied to the earth causing an upwards acceleration which results in gravitational forces. If we are using the Antarctic Icewall model of a flat earth, with magnetic north being the center of the earth, possibly the earth rotating on this central axis (like a record player) as it accelerates upwards would cause a field to be generated. The same force that is applying the upwards acceleration would apply the rotational force, thus conserving energy. In much the same was that rotational velocity can be represented by a vector angling orthogonally from the center point of rotation, so too could a magnetic field be generated.