Card potencies (class specific)

[FunkyBunch]

While that's true, that's not all there is for BLM AoE. On 3 targets you can safely use a sharp cast thunder and the extra SS would help you weave those TC procs. Not to mention the overall versatility of having faster cast times if you have to move or dodge an AoE. In the end of the day, if you dont like it you can always click it off.

Why would you ever us TC on the AoE rotation?
That costs you TWO F2 times (one for the T1 and one for the T3 proc because GCD is still GCD).
T1+TC proc=980 potency
2xF2=1080 potency on 3 mobs.

PLUS (most importantly) it slows down your Flares. Which is the entire purpose of the AoE rotation.
That is not a net gain on any day of the week. Furthermore, clicking off a buff is a pain in the butt on the PS4.

[Lilyth]

Why would you ever us TC on the AoE rotation?
That costs you TWO F2 times (one for the T1 and one for the T3 proc because GCD is still GCD).
T1+TC proc=980 potency
2xF2=1080 potency on 3 mobs.

PLUS (most importantly) it slows down your Flares. Which is the entire purpose of the AoE rotation.
That is not a net gain on any day of the week. Furthermore, clicking off a buff is a pain in the butt on the PS4.

A GCD is a GCD?
While two fire IIs take 6 seconds to cast (not taking into acount SS), a Thunder plus a TC proc only takes 5. And even then you're ignoring the possibility of another TC proc'ing for another 745.5 potency which is highly likely to happen with 2 mobs having Thunder (this is particularly fun to do when a known tank is still moving forward pulling mobs so you can keep moving with him and casting TC procs instead of scathes). I find 100 potency on an AoE pull is worth sacrificing for a chance of having a higher DPS, but that's just me.

Also you're not really losing any flares. You should always end the AoE pull with a Flare regardless of your MP so you'd only realistically lose a Flare if you delayed the rotation for around 10 or more seconds. And Fire II is only really a filler used until transpose comes off CD. You can easily swap a Fire II for a TC proc and still gain DPS (on 3 targets) while not delaying your rotation.

[StouterTaru]

A GCD is a GCD?
While two fire IIs take 6 seconds to cast (not taking into acount SS), a Thunder plus a TC proc only takes 5.

That's the heart of the issue, a GCD isn't the main factor in BLM Flare AoE. Your 2 GCD casts of 2.2 seconds each doesn't add 4.4 seconds to the rotation, it adds 6.0 seconds. Your rotation doesn't change from 15 seconds to 19.4 seconds, it becomes 21 seconds due to server side 3 second MP ticks.

(this is particularly fun to do when a known tank is still moving forward pulling mobs so you can keep moving with him and casting TC procs instead of scathes)

That is part of the pull, not part of the AoE rotation. Thundercloud works during the pull, at the start of a rotation to weave in RS/QS, and sometimes after that first Flare > Transpose while waiting on the first MP tick. After that first Transpose > Fire 3 it's a dps loss.

[FunkyBunch]

A GCD is a GCD?
While two fire IIs take 6 seconds to cast (not taking into acount SS), a Thunder plus a TC proc only takes 5. And even then you're ignoring the possibility of another TC proc'ing for another 745.5 potency which is highly likely to happen with 2 mobs having Thunder (this is particularly fun to do when a known tank is still moving forward pulling mobs so you can keep moving with him and casting TC procs instead of scathes). I find 100 potency on an AoE pull is worth sacrificing for a chance of having a higher DPS, but that's just me.

Also you're not really losing any flares. You should always end the AoE pull with a Flare regardless of your MP so you'd only realistically lose a Flare if you delayed the rotation for around 10 or more seconds. And Fire II is only really a filler used until transpose comes off CD. You can easily swap a Fire II for a TC proc and still gain DPS (on 3 targets) while not delaying your rotation.

Okay, I have now calculated it out. And there are three caveats to the data:
It assumes the PIE buff, and you get 4 (including sharp cast, which is around one more than statistically likely) TC procs over 63 seconds (without the PIE buff you literally cannot still cast the optimal F2s in the opener as you only have 85 MP left over with it) and it assumes you don't swiftcast->convert->flare.
It gets you 11402 potency over 63 seconds vs 10876 over 63 seconds. (these are some tough bloody mobs! but I needed rotations that balanced out).
These numbers were corrected for server side MP ticks. (EG-all portions where there was zero MP the time was rounded to the NEXT 3 second multiple).

Technically you appear correct, in that it's slightly better (potency wise) to use TC with 3 and only 3 mobs. IF you get 4 TC procs.
With that rotation though, you do lose out on 1 F3, 2 F2s and one Flare. So while strictly a minor potency increase, you lose out on 7 crit chances by having five extra single target spells. So I'm not sure the potency difference will actually make a DPS difference. Further, adding single target spells like TC will only serve to make it more likely one mob dies early even with proper target rotation which would again decrease potency.

To me it seems just like a way to make it seem busier with no real net benefit and rather large potential downside (losing an AoE target early) since there's no real group of 3 mobs that will take 63 seconds to kill.