If this were to happen in a boeing, couldn't you just give the yoke a tug, or are the autopilot 'motors' too powerful??
Can only speak for 737NG here but wouldn't be surprised to find the same logic in other models. In approach mode pulling on the control wheel will disconnect the autopilot rather than perform a mode reversion to control wheel steering in the appropriate channel(s). When both autopilots are engaged and below c400' RA there's a hell of a lot of nose up trim loaded up so pulling firmly on the yoke would probably be the last thing you'd want to do, it would make more sense to brace your arm for the large out of trim force then press the disconnect button with your thumb and release some of the forward pressure you're applying in order to flare, however whether or not a manual landing is practical seems reasonably subjective.