There is literary evidence that cutting off pike heads was not a primary function of the bidenhander. Two sources are worth considering, one is Di Grassi; he describes the use of the two hander in defending the standard, holding a passage, and the like.

Another is a Portuguese manual specifically on the use of the big sword, referred to as a montante, which outlines 32 drills for handling this weapon, and the circumstances where these maneuvers would be used. (This work was presented at the WMAW that just finished in Lewisville, TX.) Of the drills, one is called "guarding the lady", assuming the swordsman is a bodyguard, trying to fend off multiple assailants from his employer; others are meant for protecting oneself when being attacked front and back, or in a wide space, or on board a galley, etc. Only one drill mentions polearms at all; and the remedy for this involves beating aside the polearm and stepping in to attack the wielder; it does not mention lopping the head off of a spear/pike/halberd/partisan/etc.

Wow. My thanks to you all. I became amazingly busy very soon after I posted this, and was not able to say so sooner, but I am very appreciative for all of your help. I was right to ask here.