I'll answer these in reverse, if you don't mind. :)

So with Shark, you've got a bunch of different factions, but they tolerate each other's presence. When considering the faction relationships for this mod, I was careful to not override any pre-existing alliances or non-aggression pacts any factions had with each other. So, with the example of Hounds and Stone Rats etc, the vanilla game specifically gives them a neutral opinion of each other, and so I didn't touch that. But if they encounter Swamp Ninjas or Starving Bandits out in the wild, they will get into a fight.

Leading on from that to your first question, if there were factions who already hated each other, I obviously had no changes to make there. :) This mod, for the most part, simply adds a list of missing relationships to each affected bandit faction. When two factions meet and they don't have a relationship, they are neutral by default. So this mod makes all the bandit factions know each other, essentially, and sets them to -100 relationship.

Oh i see so the list on the description doesnt mean they all hate each other just that those factions were given hate towards those not included. Cool ty i will try this and hopefully see them hate on other bandits instead of watching them both gank me