plz do something about Astro in pvp

[Fannah]

My question may look stupid, but I only play the Frontline, and when I see people can't kill some healer players with 4 dps on them, how can only 2 dps and 1 tank can kill a healer in the Feast? Do they even do it or the healer is not suppose to die there? Are they supposed to wait to get the kill chain bonus to get them?

I'm always surprised when I see some healers looking like invincible to 4 dps and some healers just dying to 2 dps, I'm like what is the difference between the 2. Or are the dps making the difference? (or both sides I guess)