Which units are tactically more important?

I use my cav as anti-cav, so if I can kill a few Knights in order to make my cav win faster, thus freeing them up to flank the enemy line, then thats a good idea.

Same thing if I have a weakness - like only weak cav - and I'm worried about the enemy flanking me with his cav. Then I would focus on shooting cav even if it meant fewer kills.

If I can focus some foot archers and cav archers on a low morale unit on the flank and get them to rout so that I can roll up the line, then thats good too.

One thing that really helps with cav archers - get them behind a heavily armored unit, or one with a big shield, and shoot them from the flank or rear. Can greatly increase the death of death.

ichi