Long spears and pikes are a totally diffrent story though. They ARE designed to kill cav and out-distance a lance. However, their length makes them unweildy as a melee weapon unless they are packed together in a strong formation.
Well according to the unit descriptions, every spearmen above Town Militia has a "Long Spear". as you put it. the in game animations don't allways match reality. Town Militia for example look nearly identical to Militia Spearmen, yet one has a short spear and the other a long spear according to the descriptions. does raise a lot of WTF moments mind.