E1s: Heavens Sunder and Mana Slice (add cleave) were physical. The dot buster was magical.
E2s: Everything was magical.
E3s: Busters were magical, but were spaced far enough apart that you could invuln all but 1 of them in every comp.
E4s: Stone Crusher and Megalith were physical. Earthen Anguish was magical.
That's 4 magical busters, and 4 physical busters. 50% even. Dark mind is great when you can use it, and useless when you cannot. However, that said I do agree most fights have something you can use dark mind on. My point is mainly that half of the time you are using it, it is on a lower impact hit like a raid wide aoe.
To be completely fair, we would need to compare dark mind + TBN to all three skills.
Lets agree on a three minute interval since this is a reset of the warrior rotation that also lined up with the reset of TBN and Dark Mind. That gives us 3 uses of equilibrium, 2 uses of ToB, and up to about 6 uses of nascent flash, and also 3 dark mind uses, and 4 TBNs.
Equilibrium: 96k minimum healed, (up to 144k maximum)
ToB: 68.8k healed (not including bonus healing received or potential interaction with Equilibrium)
At minimum without including up to 6 Nascent Flash we have healed 164.8k.
As far as I’m aware optimal warrior play has you using two infuriates in trick attack along with a fell cleave. IC for me hits 66k on average, fell cleave hits 19k. In three hits you can do 151k damage or restore 75.5 HP. Since we can do this twice in three minutes that ends up being 151 hp restored.
During this time we also have an IR window where fell cleave will hit for around 40k. 3 hits will do 120k (if I’m clever I’ll also fit upheaval and onslaught into this for an extra 30k and 6k respectively) doings 156k damage. This allows me to restore 78k HP. At the start of the 3 minutes you can squeeze out an additional 91k from IC into IR with upheaval and onslaught, while likely wasted in the openner it isn't wasted at 3 minute marks.
Nascent Flash: 320k HP restored in the first three minutes (while only using 4 of these intervals to get this number I think we agreed that you could squeeze out 30k in healing from non burst Nascent flashes for an extra 60k restored).
Which just goes to show you why you need to do the math. Optimal use of TBN to optimal use of Nascent flash and Nascent flash turns out blowing TBN out of the water. That said, for warrior to use these heals effectively you do need to do some planning with your healers to keep you healthy enough to survive to those windows.
In a three minute interval I can therefore restore up to 485K on the low end, and up to 545k on the high end (without factoring in crit luck), on warrior while playing optimally the entire time. Warrior rotation is on a 3 minute reset time hence why I picked it.
Playing optimally on dark knight I can probably get off 4 TBN’s in this period without a serious loss. Thats 172k damage deleted.
Thats a difference of 313k HP deleted/restored, at minimum in optimal play. For Dark Mind to make up this difference in that three minute interval I would need to take 1,565,000 damage in three 10 second intervals. That doesn’t happen. If I wanted to make this up with TBNs I would need to push out 11 of them, which is about 4 per minute, at minimum this pushes 3 EoS (1500 potency) out of buff windows per minute, and it still comes up short. In most fights I don’t think you can pop TBN that often but lets leave that where it is.
To hit the high end of what warrior does I would need to pop 13 TBNs in 3 minutes, which is a TBN every 15 seconds starting with a TBN on pull I'm positive that is impossible, I think the maximum number of tbns in 3 minutes is 12 regardless, to pop that often, that leaves 1500 potency out side of buff windows per minute (IC is about 1425 potency per IC left out of a buff window when factoring in crit direct hit and average GCD). And to be super clear I think two of those 4 TBN's won't pop meaning we just straight up delete 1k potency/minute from our rotation.
TLDR; Warrior can heal between 485k to 545k while playing optimally, but takes planning with healers. Dark Knight can shield about 172k while playing optimally.