Originally Posted by
Zojha
You're just misunderstanding it.
I'm saying performance potential, not DPS potential for a reason. For DPS, performance potential largely equals DPS potential. Healers and Tanks have to heal and mitigate/keep aggro, but they can also add DPS beyond that. So their performance potential includes not just their mitigation/healing, but also any DPS they could add after meeting the heal/mitigation checks, not the DPS they could pull on a dummy with no concern to their primary function.
If I was assuming what you think I am assuming, I'd have to give Yoshidas assumption for healers 0% of their performance potential and tanks around 20%, because he doesn't assume "any" DPS for healers and only autoattack + aggro combo for tanks. I didn't, I gave them around 50-60% precisely because I am already accounting for their main job in my guess.