Before we get all technical etc:
Cavalry, in history, was overpowered in the kind of situation depicted by NW, by buffing it to the historical level it would be crazy overpowered and break the game.
Cavalry does not have the historical "balancing" of a very high cost, accordingly it has to have a cost associated with it's abilities rather than the price, as is the case ingame.
And regarding humans lacking fatigue, the human running ingame, is not really someone going at full sprint which is what you are suggesting for horses. FURTHERMORE, as I said historical cavalry charges were conducted at speeds alot lower than the max speed of the horses involved in order to maintain cohesion in the cavalry unit.
I shall discreetly interpose myself into this discussion. Respectfully, you're both right in different areas. KillerMongoose is right in respect to the fact that cavalry did charge at (almost) maximum speed, but that was only when they were close enough to enemy formations to cause maximum impact. Hekko - cavalry did indeed maintain their advances at a steady pace to maintain unit cohesion, but when it came to charging, the formation had to be spread out enough so as not to foul the charge if any men/horses were killed.
Also depends highly on what weapons/armour the cavalry were using and who they were fighting - e.g. Infantry formed up in line were much more susceptible to a full-on charge by serried ranks of cavalry, but if said infantry formed square, a head-on rush was a big no no. Also affected by the quality and training of the troops involved. There are so many variables - in real life and in NW that it's a bit difficult to map historical accuracy in its entirety with concerns to cavalry onto what is only, at the end of the day, a computer game.
I don't entirely buy this for several reasons. First of all from what I have read cavalry charges were done at a trot/walk, I won't argue about the very last seconds before impact though, but one of the reasons why cavalry kept reserves close-by was to have troops that still had their cohesion, so ruinning that by running at a gallop except for the last seconds before impact would seem very counterproductive. Spreading put on purpose is something I am sceptical about as well, because the only account of someone using it that I have read is Saxon hussars and cuirassiers against lancers, and only those two units because they had the skill and/or armour to keep them safe in that situation. Hell before the napoleonic war the winged hussar modus operandi was to start spread out to avoid artillery and small arms fire, and to tighten the formation the closer they got.
Furthermore, I don't buy the line vs square argument your selling in it's current format because you seem to be asigning magical powers to the formation in the form of a stats boost, which in real life won't happen. The two reasons I have sort of gathered and accepted as the real reasons to form a square is the lack of flanks and morale for shaky troops, so in the case of a headon charge with steady troops I cannot see any difference between a line and a square, and the fact is squares were alot rarer before the french revolution and conscription.
Another thing with cavalry is, I feel like I'm going to have the literally smash an infantry's ass to the ground and slash him on his way down as a hussar, because their sabres are too short. I was thinking on maybe increasing their sabre's length, especially how strong the bayonet is: basically preventing cavalry from directly going against them.
People seem to have some perverse need to fit hussars into some sort of battle cavalry role when they infact were not battle cavalry. The lenght of the light cav sabre is fine, on foot it has the same reach as a bayonet roughly. Furthermore, if you are hellbent on playing cav aginst prepared infantry (which is stupid, as it should be from an authenticity point of view) you should play as a lancer or as heavy cavalry.
Cavalry got buffed, quite alot last patch, it didn't really need it, but it's fine the way it is now as well.
