[SUGGESTION] Hold your fire.

[Killaim]

basically a on/off button for colonists to not shoot (but remain in drafted mode)

to many times have i sent my animals/brawlers into the front lines when i really wanted my gunners to hold their fire without having to move them or undraft them.

would be neat. thanx.

[Flare Flicker]

I don't know of any mod that does that exclusively. Combat Realism has a button that allows you to hold fire, as well as switch between snap-shot and aimed-shots.  If you have not tried CR you should, makes combat less brute force and more tactical.   

[ArguedPiano]

I second this suggestion. Would be very helpful in some situations.

[The King of Nipples]

Does anyone know how to install Combat Realism and does it replace the core

[Toggle]

You just download it and place it in mod folder. No, NOTHING replaces core.