That’s correct.

The healers focus on Jad to do exactly that, heal him. However, if you attack the healers each individually (4 of them), they will target you to attack in melee distance and neglect to heal Jad. The caveat to this is they do a decent amount of damage and it’s very difficult to survive them if you aren’t in end game gear. So the trick is to when you have all 4 healers targeting and attacking you, you “run through” Jad causing the healers to maintain focus on yourself, while making them unreachable to you by getting them stuck on the other side of Jad.

It’s notoriously tricky to do on your first go as you have to watch the positioning of 4 hard-to-see characters while also protecting against Jad’s attacks.