Nekos fight machines, vampires fight humans, demons fight angels, mutants fight anyone. Thats all before the various groups come into play. Its one big war zone.
There never seems to be any end to it. Why fight at all? Its not like Toxian City has any real resources to fight over in the first place.
At least if you do fight try and be a bit more organized. Most "wars" in Toxian City are more like playground fights in school. Someone calls someone else a name, they rise to the bait, lots more name calling ensues which draws a crowd, They egg the participants on until one of the finally physically attacks the other in some way.
Even RL gang turf wars are better organized. Either go down the silent assassin route and take out your foes quickly and privately or go down the military route and set up a proper ambush with backup and stuff. Call your target out in the Haven or somewhere and then take him outside where you friends are on the rooftops with sniper rifles and or heavy weapons ready to blow them to smithereens. No quarter asked or given. Then if their friends join the fight your are in a good tactical position rather than just a melee in the street.
If any one of the various factions tried either of these tactics they would be running the place withing 2 weeks.
Thats why the rules of Toxian City try to prevent such things. Technically you cant just open fire on someone without warning. So assassination is against the rules. Ambushes would fall into a grey area as far as I can see.
The other limit is getting enough people on line at once to back you up.A proper battle would require a lot of people with different skills, abilities and weapons. Most of the time that good mix wont be available to a group leader. Of course if it was the odds are there would be no one else to attack in the city, unless things were highly preplanned. But who wants to plan being killed and your group being killed too.
So the petty arguements rage, people bully one another and life continues.... ah Toxian City, were the sound of gunfire is always in the distance, if your lucky.