Ganache

Hi a quickly I’ve got a wedding cake to make 3 teir she wants ganache drizzled over the top running down the sides now I’m covering cake in white frosting as im not sure pouring ganach over gondant wi work so should I sack first cake and pour second cake and pour then third as if I do it one at a time I won’t beable to the stack each cake as lifting will leave finger marks in the drizzled ganach is this right