I in fact think that vanilla Halberds are bad units - i guess the concept is that they were kind of MTW Naginata, however with Heavy Cavalry being as strong as it is, they would have work much better if they were a scaling down of Chivalric Knights in stats, ie units that make up for their slow speed and high fatigue rate, by good morale and attack. As they are they can win battles of attrition, since they have low attack and high defence, however fighting for long and hard is also not their forte due to the tones of armor and low base morale.

its true of course that upgrades and a good general can make up for these but when you have provinces that can churn out highly upgraded troops i'd still go for Militia Seargents. Its down of course to style and all styles are good.