Viscous Swing + Striking Critical Hit

[Riggler]

I thought this was really simple, but after a game last night I'm questioning myself based on the Counting Damage Dice rule on Pg. 406 and the massive damage unleashed by a level 4 fighter in last night's game.

A fighter with a +1 Striking Greataxe critically hits an opponent using the Vicious Swing Feat. They are doing 6d12 damage + double Strength mod? Correct?

[Baarogue]

(3d12+STR)x2 unless the GM allows them to roll double dice instead of doubling the result of the normal amount of dice, in which case it would be 6d12+(STRx2) as you say

They're both the "same", only the normal way is swingier and the double-dice way is a smoother curve of results