For the purposes of modding, I want to change the default behaviour of missile units so they always engage in hand-hand combat when the enemy closes range. Currently, the default behaviour is for archers etc. to pull back and try to increase range until they feel 'safe enough' to re-engage with their primary weapons.

However...if you toggle the skirmish button off, they switch immediately to hand to hand once the enemy get in close. Is there any way, either by script or preferences etc. that I can change this behaviour so the units are automatically in this state, and you have to click the button if you want them to 'skirmish'

I get two benefits from this...

1) Missiles still get fired up close by any units not directly engaged
2) The units don't run away unless morale drops and hold the line properly