It could work in the fashion of the total war series. The enemy faction breaks completely or does an orderly retreat you could get a window asking you if you want to fight on and maybe get some of them or let them go and end the battle right now.
If you fight on you should have the option to end the battle later at any point in case you realise you cannot chase them.
"I am a Paladin!"
>OMG, Malthus, there are no damn paladins in Battle Brothers...<
"OK, OK! Then I´m a wrecked down minstrel drunkard pretending to be a paladin, singing so wrong in the midst of battle that even the undead run in fear... Better?!"
