5 orbs if someone shoots your bubble, +1 orb for every melee in force barrier, and then Iron Harvest is RNG. Defender Titans have the potential to spawn more orbs than any other class, but rarely get the opportunities to produce them all. Sunsingers get 15 grenades that can kill 3 red health enemies each, that's 8 easy orbs as long as there are enemies. So in closing, Warlocks can produce their 8 orbs easier, but Titans have to potential to create many more than 8 orbs per super.