Miasma: 20 potency on cast and 35 potency over 24 seconds:300 total potency (20+(30x8))
Pre ShB Bio II: 35 potency damage over 30 seconds (total potency 350)
Total dot potency: 650
ShB Bio II: 50 potency damage over 30 seconds. (Total potency 500)
Difference: -150 potency
However: Miasma costs a gcd, with it gone, that is replaced with a cast of Broil II.
Broil II pre SHB: 230 potency
Broil II post Shb: 260
12 gcds in 30 seconds assuming 2.5 second gcd
Sb rotation: M, Bio, B, B, B, B, B, B, B, M, B, B
ShB rotation: B, Bio, B, B, B, B, B, B, B, B, B, B
Miasma Total Potency
300+20+30=350
Broil II Total Potency:
Pre ShB: 230x9= 2070
Post SHB: 260x11= 2860
Bio II total potency:
Pre ShB: 350
Post SHB: 500
Pre ShB: 350+ 350+ 2070=2770
Post ShB: 2860+ 500= 3360
Assuming no clipping/ogcd use, ShB rotation is ahead by 590 due to not needing to cast Miasma.
Without clipping the gcd, the best chance to weave would be the bio II cast, so assuming we add an Energy Drain and a Shadow flare there...
2770 + 150 + 250= 3170
Alternatively you can use swiftcast to gain a weave space and an extra energy drain
3170 +150= 3320
Finally, replacing one of the Broil IIs with a Miasma II
3320-30=3290 +150 = 3440
3440- 3360 = 80
Unless you spend all your aetherflow on ED in this 30 second window, you are dealing more potency in that time frame with the SHB rotation. I admit their are other factors, such as using Dissapation. But I'm trying to assume an average 30 second scenario
To be honest, our potencies at lower levels are irrelevant to me considering that the healers are not the only ones who suffer from this issue. But the potency differences in a single target setting are nowhere near as severe as you think at current levels and beyond.
Considering the fact that Ruin II gains its potency with each rank of Broil Mastery at that level range Ruin II will also have 100 potency. And while on a pure potency basis AoW will be stronger, this is bad use of your MP and inefficient for single targets.