https://gyazo.com/c0e56e8fc3d148fced7d218bef726b31 crude 30 second paint picture to explain;
Yellow is the middle of the circle. Blue/purple/green squares are the plasma orbs.
P1 is simple, just keep the bosses as still as possible, and kill orbs. We kill Blue->Purple orbs personally.
P2 we move the boss between blue and purple orbs to cleave lashers. Call of nights try to stay within the purple triangle, to let the rest of the raid use the middle of the room.
P3 gets a bit more tricky - we stack in the middle (yellow), making sure not to get hit by the tank. The first two calls move out to the red marks, one each, with a partner. When they get solar collapse, we run to the cyan squares, then on the next collapse, to the red - back and forth, back and forth. You're out of range of the raid in the middle like this.
When you get to second call of night, have them suicide into the spores instantly (make sure someone walks them out there so they don't pulse the raid). Same with third and fourth (should you get them)
Reason for this is that nothing happens for the first 40 out of 45 seconds of first call of night, so wasting 2x battle resses on them is fairly dumb. As long as you get the 2nd nights killed, it's all going to be fine and you'll have more people alive.
After second set of plasma orbs we dispel the debuff on tank and move to the bottom yellow square, and tank there till the boss dies. We kill purple->green orb in that position, and we're super close to the spores on both sides for suiciders.