You're applying a mechanic from Warrior to Red Mage when it isn't required. All I said was just a permanent slash rather than a reduction per verfinisher fits them better. The warrior is working against several different factors when it comes to their Beast Gauge expenditure - Critical Bonus, GCD Delay, Utility of the ability, and so forth.

The Red mage does not. They will only ever use their AOE combo for mass trash, so dungeon pulls where balance rarely is a concern or in one fight this expansion for raids where it was more about heavily padding. In the same vein as giving Merciful Eyes threat reduction, giving Red Mages a per-finisher reduction is effectively just a permanent bonus anyways, so just slash the base CD.