Also, as it is true that the M&B measuring system is not metric, the Pike in game is equivalent to that of a rather short pike; I am suggesting a thrust-only long pike that is well within what was actually used in real life while still being balanced in game.
I am not really sure Warband uses metric system.
Sure, the length of all one-handed and two-handed weapons weapons fits into metric system perfectly, yet "it is true that the M&B measuring system is not metric".
Americans...
Original M&B pike is about 3-3.5 m long.
Off-topic
Not true but only because the Swiss brought out the pike wall to counter the heavy cav based armys of the time, and totally revolutionized feudal warfare. The pike square was pretty much a new and improved version of the Phalanx.
At the very beginning of their strugge, the Swiss used halberds, they started combining halberdiers with pikemen after they realized that a short halberd by itself couldn't serve as an effective anti-cavalry weapon. With time, pikemen to halberdiers ratio increased. So, it was not Swiss who "brought out the pike wall".
The revolution in the late 15-17th century warfare has nothing to do with just pikes. It arose mostly due to the novel army recruitment system.