Seems Wind I is useless now

[Zfz]

Also if you're wanting to do purely DPS then you'd want to use Aero>Aero II>Stone anyway so it's irrelevant. Using Aero then Stone would be more overall dps then just using stone.

The point that op is trying to make, is that the GCD you spend casting Aero for a sum of 200 potency, could be used to cast another Stone 3 instead, which has 210 potency. You're actually worse off casting Aero + Stone 3.

In other words, the only time when you're better off using Aero is when you cannot complete your cast of Stone 3, which means, if you're not moving, don't cast Aero at all. Use that GCD to cast Stone 3. Only cast Aero when you are already moving, during which time you cannot cast Stone 3.