I leveled a hunter last time we had this event and for the first 40 levels I did full spear or sword and beastcraft. Just group up, hit everything that moves, and shoot people if you get rooted. Then once I hit 40 I started soloing and specced more in bow and stealth. Kept bow relatively low, never went above 27 until I hit 50.
40 BC, 39 spear was what I always aimed for, keep stealth as close to composite as you can and just put the rest in bow. But like I said, I was soloing once I hit 40, if I were to keep grouping I probably just wouldnt spec stealth and go full melee and beast.