It's true--you are almost certainly not going to be able to solo a decent healer. But you are an amazing asset to your team by applying this kind of intense and relentless pressure on a healer, and if a dps decides to help you at some point, healer often dies. In half the matches I play that are 8v8, I out-dps 5 of the 8 dps (partly because of the survivability and uptime of war).

And yes absolutely burst the same target with your team mates to start. But, you will find that most groups then want you to STAY on the healer, regardless of thwat the dps does--they may join you at times, or pick off someone else. Keeping this high pressure on the healer creates opportunities for the dps to make kills.