According to Wikipedia:
German and Scandinavian medieval armies made extensive use of mounted crossbowmen. They would act not only as scouts and skirmishers, but also protect the flanks of the knights and infantry, chasing away enemy light cavalry. When the battle was fully engaged, they would charge at the enemy flank, shoot a single devastating volley at point-blank range and then attack the enemy with swords, without reloading.
This seems like it would be quite a cool unique unit for the HRE. Heavy cavalry that fire a crossbow bolt as they charge. Just wanted to mention it!
Not really, most Central and Western European armies included some form of mounted crossbowman. so it really isn’t anyhting unique to the HRE or Scandinavians.
Well, first, it wouldn’t need to be a unique unit. I wouldn’t mind giving it to other civs.
Second, many of the civs unique units, especially in AOEIV, aren’t technically unique to them. Other nations did have longbows, they were a bronze age celtic weapon that were most strongly associated with the English but found all over the place. The Chinese “nest of bees” style weapon is often more closely associated with the Korean military (the hwacha) to the degree that I imagine its status as a Chinese UU might offend some Korean players. Camels weren’t used exclusively by the Abbasid. Elephants by the Delhi. Arbalests or cannons by the French. So in AOEIV terms a unique units is really only unique to the civ in-game; it doesn’t mean it was unique in the real world.