I am of the "cavalry is powered less than RTW" school too. I hold my generals until they have the chance to charge pinned or depleted units, and then from at least a flank, usually. No trying to maneuver for a simple open flank or rear on a standing or marching unit. If their target turns to face the charge, the payment is too steep and the risk of a morale hit high. If the target is moving too much, the charge is too likely to fail.

And light cav gets hurt badly if they don't do likewise. But in pure pursuit they are great. They also work just fine in charge mode to close the noose around a unit, though leaving the unit with no escape route can result in a lot more cav casualties. Better to follow Sun Tzu and give them that gap to flee through, then you can send the cav off to round up prisoners with little risk.

But this is all sorta realistic and sensible.

I do love my jinettes though.

Based on my one-on-one unit charge tests I am confident heavy cav can bust a similar spear wall, but at a high cost. The difference in charging frontally and into a flank or rear is more in the casualties to your cav than in the resulting instant destruction. Charges hurt.