Hit it and quit it

Any cavalry unit that can “pump” — charge, break free and charge again — should do so, as a rule of thumb. However, this is more important — and possible — for some units than others.

Any cavalry unit can batter infantry in this fashion. Doing the same thing against opposing cavalry is more problematic.

This is a ranking of units whose primary attack plus its charge is more than 1.5 times as powerful as their melee attack value, even after any anti-armor bonus for the melee attack is applied. Note is also made of their speed. Bodyguard and Monastic Order knights are not included:

Condottieri — normal
Italian MAA — slow
Mercenary Knights — slow
Polish Retainers — normal
Latinkon — normal
Broken Lances — normal
Portuguese Knights — slow
Gendarmes — slow
Alan Light Cavalry — fast

Next comes units whose charge is 1.5 times as powerful as their melee, and which have normal speed:

Christian Guard
Serbian Knights
English Demi Lancers

1.5 charge, slow speed:

Mercenary German Knights
Imperial Knights
Polish Knights
Chivalric Knights
Eastern Chivalric Knights
Polish Guard
Noble Knights
Royal Banderium
Lancers
Famiglia Ducale

Stay and Play

At the opposite end of the spectrum, we have units that should “pump” against infantry but should never allow enemy cavalry to break away and charge again. They should get a grip on their cavalry enemies and never let go. They have a “pump rate” of 1.33 or less:

Albanian Cavalry — fast
Stradiots — fast
Mamluks
Merchant Cavalry Militia
Kataphractoi — slow
Armored Clergy — slow
Huscarls
Quapukulu — slow
Royal Mamluks — slow
Druzhina

Here’s some more that should consider just slugging it out as an option, with a “pumping” rate of 1.4 or less. All have normal speed unless indicated otherwise:

Gothic Knights — slow
English Knights — slow
Hussars
Conquistadores
Norman Knights
Serbian Hussars
Crusader Knights
Tsars Guard — slow

What's left?

Here are the units that have no clear-cut option in this particular category, ranked in order of the superiority of their charge over their melee factor. Speed other than normal is noted:

Mailed Knights
Granadine Lancers
Mercenary Frankish Knights
Armenian Cavalry
Sipahi Lancers
Feudal Knights — slow
Kwarizmian Cavalry — slow
Tuareg Camel Spearmen — very slow
Border Horse — fast
Italian Cavalry Militia
Byzantine Lancers
Mounted Sergeants
Arab Cavalry
Bedouin Cavalry
EE Cavalry Militia
Greek Militia Cavalry
Scouts
Hobilars