Now that I have the amount of cavalry I need to simulate 2 cavalry armies opposing one another, I finally fought a battle with them (2 generic Asiatic Horde cavalry armies). I had to hone a few my rules (and markers) to handle the sheer amount of charges/counter charges so that it could make sense to the players.
Needless to say, Cavalry/Cavalry battles are much more fluid (and fast-paced) than the usual infantry-heavy army battles. What usually is a 10-12 turn game turns into a 4-6 turn game. It also is hard to recover when a mistake is made (and it is easy to counter-charge the wrong unit, fail a counter-charge roll, a morale roll, or whatever.)
Side A (which I used Mongol cavalry) had less light and skirmish cavalry than side B (which I used Huns and the other miscellaneous horse barbarians I had- Alans, Pechenegs etc), but had more heavy cavalry.
Both sides closed in and used a little archery to try to create an opening that could be exploited. However, the sheer numbers on the field (approx 8000-9000 cavalry a side) made little dent in either side, despite the flurry of feather shafts.
The Mongols finally had enough, and started charging through the thick Hunnish cavalry screen and managed to maul them pretty severely before being checked by the much less numerous Hunnish heavy cavalry. The surviving Hunnish Light Cavalry started scoring hits with its archery, and the less numerous Mongol Light Cavalry was innefectual.
The battle hung in the balance, until the Huns started failing morale checks. With their heavy cavalry starting to flee the scene, the Mongol heavy cavarly got the upper hand. From what was a stalemate just 2 turns before, the battle had turned into a Hunnish rout quickly.
Final result- the Mongols actually took more losses (approx 2400) compared to the Huns (approx 1200), but the Mongols held the field at the end. Since I stopped the battle at the moment of the rout, the Huns would've suffered even heavier losses in the pursuit if I had gone that far. But as much as that would have been a more realistic end-result, it would not be much fun for the players.
All in all, the rules held up well with the massive charging/counter-charging that occurred. It was a fun battle, that when both sides came to grips, was over pretty fast. A little more skirmishing for the Huns would've been better as it favored their light cavalry advantage, but the Mongols should try to close as soon as possible to take advantage of their heavy cavalry advantage.