A few ideas that come to mind is
Ninja Cappers - 1vs1 or 1vs2 (maybe) with some good cc coordination and skill you can easily defeat most opponents and ninja cap flags for teams which can lead to victory
Flag Carriers - with the 4p PvP bonus (15% increased movement speed while outdooors) and the base speed boost from being a feral you can rapidly run a flag from A to B in no time. The ability to shift out of roots and snares also helps this.
Peeling for team mates - Predators swiftness procs can be used to peel enemies from your FC or healer with instant clones, roots, stuns then there's the snare attached to feral charge and shred/mangle (infected wounds)
Dealing with healers - there aren't many healers that a feral can't combat against with their stuns, interrupt and instant clones you can lock down a healer with ease
These are the things that I mainly go about when running BGs and trust me ninja caps etc win games