I must be missing something, because I didn't get anything like those numbers...
Code:
3 * 0.25 ( 60 / ( 2.36 / 0.12))
0.75 * ( 60 / 0.1966667)
0.75 * 305.08469
= 228.81
The actual formula for elusive brew is simply:
1H: [1.5*WeaponSpeed/2.6]
In words:
If your auto-attacks crit, you get either 1 or 2 stacks of elusive brew, which alternate keeping an average of 1.5, assuming your weapon speed is 2.6.
2H: [3.0*WeaponSpeed/3.6]
In words:
If your auto-attacks crit, you get 3 stacks of elusive brew, assuming your weapon speed is 3.6.
If your auto-attacks crit, WITH 3.3 WEAPON SPEED you get 3 stacks of elusive brew 3/4 of the time, the other 1/4 is 2 stacks.
Therefore, the chance of getting an elusive brew proc is the same.
The exception with this comes to if you want to look at crit and the attack table. Dual wield would require more expertise to get through the higher parry rate (that the second 1h weapon would bring). However, this isn't until you have enough crit to fully overtake your hit chance. (Crit would eat into hit first, then conflict with parry chance).
Basically, the only difference is that dual wield 1h means that you get a slightly steadier stream.