This is one of the large scale battlegrounds, and to be honest my knowledge of the overall strategy for this one is rather shady.
With very little to do when it comes to handling enemy players I usually ride to the very opposite end and start picking off archers and burn down two bunkers.
While I wait for more people to join I continue killing off the NPC:s, and eventually I swap to my PvE tanking gear and hit the enemy boss when we're ready for the final assault.
I'm a bit unclear as to how important it is to clear out every NPC at the enemy starting base, but in order to make the ordeal as short as possible I'll drag the elite ones out of their buildings and tank them in plain sight of my team mates. This almost inevitably leads to them being burned down in seconds as people have a tendency to attack anything that is being fought close by.
The final fight is a pure tank and spank fight with no finesse involved at all. Don't forget to swap to PvE tanking gear as it makes the fight a lot easier for your healers. You can't do anything about remaining enemy players more than pray your team keeps them CC:d rather than getting involved in in an outright fight as this slows down the boss fight considerably.