I think the point is that in M2TW nearly every single unit with 'Spear' in it's name is exactly the same, save for the colors. Such things, but if I'm mistaken then the thread really is about - gah, Medieval warfare is just a bunch of all guys wearing basically the same, and not about - gah, CA creates a game, and isn't concerned with adding any variety at all.

If it's about history, then the great invasions that had taken place before the game's timeframe may explain why most units are the same. That is because there is basically one dominant culture, with one dominant fighting style - that of the Romanised Germans. It has developed over time, of course, and thus it isn't remarkable to see there were actually big diferences between say the South and the North - but still, all the basics are pretty much the same. What can't be explained by these lines of thought though is: 'why on earth are the Saracens wearing Norman equipment?'