I know why it's there, and it makes sense, but it is exploitable, particularly as no matter how low the firepower $, a few horsemen skirmishing away seems to do comparable damage to full volleys from infantry units.
It's probably harder to (ab)use against a player than against the AI, but it's one of a few "broken" features (the ability to initiate "cold steel" and then do anything but attack the enemy with the movement points being another) that might just lead to a competitive game getting ugly.
That said, I'm up for a game of Asch or Habelschwerdt, just to see how fire-capable cavalry actually plays out PVP.
Habelschwerdt has one Austrian unit (IR 59 Daun) with 1/0 range in the 1.12a version though, and thus incapable of firing.
no truth - no justice
all false belief
blinded by morality
there shall be ... no peace