I've had interesting results where I double click on the ground - to make a destination - rather than on the enemy unit.

This is foot units I'm talking about here but could equally apply to Cav.

Where my unit's only straight-line route to the destination is through the enemy unit, they will run at full speed, crash into the enemy, be brought to a halt and will then fight it out. If they win, they will advance to the spot I told them to go to and then, vitally, STOP.

This is for battles where I know the AI has shedloads of reinforcements to come onto the field and I know my attention will be divided for the time between ordering the unit to engage and it finishing its fight. This ensures that it will break off from pursuing routers at the place where I want them to stop and I retain overall cohesion. Divided attention factor means a plain attack order will have my men chasing them across to the back end of the field then, whilst out of my sight, becoming a sitting duck for incoming enemies.

I've yet to have a chance to test this next bit but I hope to use the same technique to get a cavalry unit, in wedge, to strike a unit in the flank, push through the unit and out the other side, breaking up their formation and disengaging without having to do a risky 180deg turn in the middle of the meleé. Once out in the open, they can reform and I repeat it in the opposite direction, if needed, using the same technique.