People from same group tend to not attack each others at the begining, they will prefer to target low levels and weak players 1st (or even clones) then when all easy prey got eliminated they fight each other for fun.
If you are surfering camping, you can ask for help from your group mates and fight them back. But that only work if your group have some strong players in top 10 (at least 2), if your group don't have any strong people then use tanky team, if you can't beat them then stall them. Eventually they will reconsider everytime they want to attck you. I used to be camped by top 3 spenders from the top 1 group (I was top 8-10 at that time) but then I started to stall them and build a defensive team, once I beat 1 of them and gave others 2 a hard time they just stop messing with me. Good luck.
And like the guy above me said, cross server swb is not a good option.