I hadn't tried playing with Xorberax's legacy mod until quite recently and I was sceptical of how good the (melee) friendly fire incorporated to the base game would work, but I was pleasantly surprised in general (except for narrow street battles with Fourberie). I honestly think that the devs should consider adding the option of melee friendly fire to singleplayer, it already existed in captain mode the last time I played (though it was a while ago, during the multiplayer beta prior to the EA so I'm not sure if it's still a thing), thus I'm assuming that it wouldn't be hard to implement either.
