This is how I see 4 wars working with a healer.

If they get cc-ed and bladestorm is on cooldown, they do in defensive stance and spell reflect until CC expires (by CC i mean immobilization effects, anything else lets you charge/intercept, fear is not an issue for wars at least not much).

In the meantime they stay clumped together and the healer keeps healing and dispel if possible. When freezing effect expires you go back to battle stance and charge or whatever.

If another melee is stupid enough to come near you while you're frozen than you pound on him.

This can work as long as you are surrounded by at most 3 ranged chars. In arena there's always a melee or two, and there's 2 healers so that leaves you with 1-2 ranged classes hitting you while you're stuck. That's healable dps.

If your healer gets trained he will heal himself. Any healer can heal today dps from 1-2 classes.

If melee comes near your healer you pound on him, because your healer will be near you all the time or almost all the time.

Well, this is all in theory, we'll see how it turns out.

About priest, does mass dispel work on friendlies too? I thought it only dispels stuff from enemies.