Rebalancing cavalry with working charge bonus?

[Zero1]

In fact, Roman infantry was very suceptable to cavalry attack when not in proper formation, as the mounted attacker had an advantage in both leverage and height which rendered the gladius somewhat impotent.

Well, if I remember correctly, when the Romans were expecting large cavalry assaults they would use their heavy pilum in tight ranks presenting a sort of loose phalanx or spearwall to compensate for that very problem with the Gladius. Also, after the initial charge that becomes less of a problem because it becomes possible to get up under the horse and stab at it's belly more or less disemboweling it. And on the note of proper formations, pretty much any infantry is vulnerable to calvalry attack when not in proper formation not just Roman infantry. A well timed heavy calvalry charge on a unit of soldiers out of formation will rout pretty much anyone.

Of course, I'm no expert, I'm just well read on certain things