1. If your INf are 2h or hi-attack/ap better to charge in, if theyre hi-defense better to sit and wait. ie unit dismounted (random faction) knights charge in ... pikemen wait.

2. you can make this easier on yourself by separating your front line into unit types
and have all your defense units bunched together with the other units and the cav supporting on the flanks.

3. depends on a the ground abit too, if you are on a large hill better to have all sit and wait so as to use the height advantage to the maximum, but all in all point 1 is prolly the best option.

4. if you afford too much time into the charge and you charge too early or after a unit that is faster than yours and retreats instead of engaging, you can put your units out of position easily so micromanaging your counter-charge is a good idea.

5. always charge your cav as opposed to letting them "take the hit"