I use light cavalry to chase routing units. They are much faster do a better job. Turn off fire at will (if they have that option) to catch more prisoners if that is your aim. You can also reissue the attack command as they may have destroyed that individual unit in the blob of routers. I usually give them a minute or less to get some good kills but once you end the battle the AI calculates you running down a certain amount of stragglers as POWs.

I didn't know that. I thought you had to physically get the routing units "killed" to get pows. Been a tradition of mine to pursue every single routing unit I could since the first Shogun.

Yeah I don't know how the calculations work but if you end the battle right when it lets you then units that didn't see combat will get some "kills." Very rarely in history did armies do extensive running down of routed enemies. Gaugamela was one and Alexander lost alot of horses after that due to over work.

Ancient historian sources are not entirely clear on the exact number, but one source, Plutarch (via Arrian), suggests that more than 1,000 of Alexander's horses died at Gaugamela, either from wounds sustained in battle or from sheer exhaustion during the lengthy pursuit.

This was more men than he lost. The AI doesn't chase your routing army after the battle.

Interesting about Gaugamela. The other battle that comes to mind was Cannae. No Roman survivors except the small garrison that didn't participate. I doubt all the Romans died fighting to the last man. Many surely ran after being suddenly cut down from all sides.

Likely correct. Though i don't remember reading about Hannibal's lack of horses after the battle. If you run a horse too long it can break them long term. This is what Arrian discussed. But an interesting discussion.