I haven't found any use for this formation except for receiving horse charges which rarely happen.
I've noticed that units that have the ability also have "very long spears". This was represented well in RTW where they were able to defeat spearmen with short spears, but here I don't see any signifigant reach advantage.
It seems like all of the units that use this ability are weak compared to their non-spear wall using counterparts. For instance, Janissary Heavy Infantry are very powerful (probably 2nd or 3rd strongest infantry), yet the Danish special halberdiers are damn near useless. I remember playing as Sicily and finding out that my halberd militia were useless compared to Italian spearmen.
It just seems like their formation is not used the way it should be. A solid block of men wielding halberds should be formidable. Don't even get me started on pikemen equipping swords when one enemy makes it near to the flank.
Have modders noticed this or is it considered a non-issue?
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Ohh one more thing. I noticed that the only mod I've played to date that gets climbing siege ladders and towers right is The Long Road. I prefer playing here, but is there a way to analyze his mod in order to get it right? As it is now, I get beaten by a few units of peasants when I use 2 towers filled with swordsmen. They simply do not climb up the ladders like they are supposed to and they don't seem to react very well when they make it up. I see them standing there getting stabbed and doing nothing at times. I've resorted to just making catapults and destroying all the walls so I can enter and not lose my best units due to the bug.