This is kind of a silly question, but can mercenary mounted crossbowmen and horse archers fire while riding, or must their mounts be still? How about veteran versions of the same troops?
Interesting question. Obviously, I am not an Autarch, but I will note that in Domains at War: Battles, Crossbow and Arbalest armed troops cannot fire if they do anything other than Stand Fast during their Movement Sequence.
Mercenary horse archers, and PCs capable of using bows with Riding Proficiency, can fire and reload while moving at up to 1/3 speed.
Mercenary mounted crossbowmen, and PCs capable of using crossbows with Riding Proficiency, can fire while moving at up to 1/3 speed, but cannot reload while moving at all.
Interesting. Why 1/3 speed with bows?
It’s simply the standard rule that combat movement rate is 1/3 full movement rate.
Ah! I was thinking it was 1/3 of that for some unknown, arcane reason.