In ancient and late medieval combat, the pike emerged as a supreme weapon, an evolution of the spear. The pike being longer than any other melee weapon, a phalanx of pikemen would skewer the front ranks of an enemy formation before the enemy formation could bring their weapons to bear. Naturally, longer pikes beat shorter ones, and this was seen through the medieval period as pikes often became longer and longer when both sides were using them.
However, there is a limit on the practical length of the pike. Beyond a certain length a pike would be too heavy for one man to handle. But a pike that is too heavy for one man, might not be too heavy for two or three men working together.
So my question is this. Could it have been practical for a military with medieval technology to use a few "crewed" polearms carried by several people, as part of a normal pike formation, to be the first strike? We might imagine a 50 foot stout pole carried horizontally by three or four people like a battering ram, with a crossbar or fork on the end so it could knock over several enemies and break their formation, after which the enemies would be finished off by more conventional weapons.