According to the hearthstone wiki page, whatever card is closer to the top of the deck triggers first. So in theory, Baku should have the same success rate as Genn.
Maybe it was designed to allow C'thun the Shattered to work in either odd or even decks, but is either bugged or intentionally random (not sure why it would be random, but maybe they programmed based on order in the deck)?
Edit: There are a few apparent inconsistencies here if - Prince Malzechar apparently works consistently with Genn, the actual wording "start of game" wording is the same, and also apparently Baku never activates with C'thun the Shattered?
hearthstone.gamepedia.com/C%27Thun,_the_Shattered
According to the hearthstone wiki page, whatever card is closer to the top of the deck triggers first. So in theory, Baku should have the same success rate as Genn.
Maybe it was designed to allow C'thun the Shattered to work in either odd or even decks, but is either bugged or intentionally random (not sure why it would be random, but maybe they programmed based on order in the deck)?
Edit: There are a few apparent inconsistencies here if - Prince Malzechar apparently works consistently with Genn, the actual wording "start of game" wording is the same, and also apparently Baku never activates with C'thun the Shattered?