Quote Originally Posted by jhhowell
Make sure you alt-click when you order a charge that you want to end in sustained melee (against an enemy general, most commonly, but also for the infantry-busting you describe above). Not sure what exactly Bactrians carry as an alternate weapon, but most heavy cav out east has a nice strong AP weapon for melee. As I understand it, the tradeoff is a loss of lethality from the brutal 0.4 of the lance, but you gain quite a lot of attack score (more hits) and attack speed (hidden stat, not on the unit card, I don't know much about this and am repeating hearsay from this forum ). I and many others find this a valuable trick, others have argued it doesn't do much. I haven't seen reports of any detailed tests.
I think the experience of the cavalry in question has a big say here: Consider an exp 0 unit of Hetairoi, they would have a 5 (0.4) + 37 lance attack, and an 11 (0.11) + 18 sword attack, both armour piercing. So here, the basic attack score of the sidearm is more than twice that of the lance.
Now, consider the same unit at exp 7: 12 (0.4) + 37 lance, 18 (0.11) + 18 sword. Here, the sidearm only has a 50% higher basic attack score. I believe that this means that at some point, the lance simply becomes the better weapon all round, at least for most hellenic and eastern heavy cavalry.
For brihentin and similar units, with their lower lethality lances/spears and higher lethality, non-armour peircing longswords, the sidearm might always be the weapon of choice in continual close combat, at least against low-armour enemies.