A test of your prowess, the endless gauntlet - a continuation.

[CNFish]

At the most optimal position color spray can get 5 of the 10 goblins.
RXXXR
XGGGX
GGOGG
XGGGX
RXXXR

Where G is a goblin and O is the grate. If you came at them from the corner (R) you would be able to get 5. Do you accept this wilphie?

Will assume those closest to robina passed the checks. So which means, only one of those AOO would be from one that passed out.

So to make it a fair chance. (1d100)[78] 1-50 is the first goblin, anything higher than that is the other goblin. Which ever the roller decides is the one that was knocked out and incapacitated by robinas spell.