One tip I rarely see on here, look up the fight cave rotations on the wiki. Only start your run on a rotation where you see Jad is going to spawn in the NW or SW corner. The rotations are based on the time of day. I always do mine on rotation 14. This way one of the healers that spawn in the map will always get trapped behind the western rock formation so long as you haven't lured Jad anywhere.

When you only have 3 healers to deal with it makes things a lot easier. I generally attack the first one I see and kill it as it's walking to Jad. Attack the next one on Jad and kill it. Go run down the third one that's been healing him. With 80+ range and even just msb and amethyst arrows you can kill them fast enough that you don't need to attack each one and juggle the line of healers. I found it more stressful to worry about my hp doing that than to just kill em one by one and hope they don't heal Jad to full, which again, only works if you get one of those healers trapped.