Instead of being restricted by an overly complicated technology, the Flemish Militia should be simplified by lowering their armor class to that of the spearman, and keeping their cost the same as regular spearman units.
A comparison can be made between Winged Hussars and Regular Hussars.
If we apply this same logic to Flemish Militia, they would have slightly higher stats than the Halberdier with +5 HP, +2 attack, and +1 melee armor for an upgrade cost of approximately 450 food / 700 gold.
Their line of sight (LoS), speed and rate of fire would remain the same, while the bonus attack values could be adjusted based on whether they should be similar to pikemen or halberdiers.
What are your thoughts on this idea?