There's nothing more tense than a turf war between two hard swinging crews. If somebody is moving into your territory, my advice is threefold.
1. Hit first
2. Hit hard
3. Headhunt. Ignore the low level guys, they're easily replaced, it's the crew boss you want. Kill him where he lives as a statement, oh and leave no male heirs. You don't wanna face some Count of Monte Cristo style revenge **** 30 years from now do ya.