While you on the other hand must think the polar shift happens instantaneously without any variance of the field strength?
Sure, buddy, sure.
It seems that your tendency toward personal projection points inescapeably to the inherent collapse in your arguments. While radical if not instantaneous polar shift has certainly been speculated, it has not been formally observed, nor have we come to expect that our compasses point to "S" one week and to "N" the next.
Decay in the Earth's magnetic moment has been and is measured and observed. For your point to have any testable merit you would have to be able to humanly witness a radical polar shift. Until then, your position is all speculation and is based in mere theoretical supposition. But then again you are the one still trying to get us all to imagine the Earth orbiting Saturn.
You are welcomed to speculate about whether the magnetic moment of the Earth has undergone realignment, it is, however, an incontrovertable fact that your imagination (if not image of yourself as an accomplished scientific thinker) is in need of some serious re-alignment.
I on the other hand will continue with an observed and a recordable phenomenon.