A Confused card mostly always hits a frontline because you kinda have to take out the frontliners first before you get to the rest of the creatures on the board.
If you have 1 frontline then by default a confused card will attack it because what other choice does it have.
When you have 2 frontlines now the confused card has a 50-50 option on whome to attack.
No idea if this mechanism works the same or differently on Hearhtstone, but if it works like this with GU, then I accept it haha. So, you first, always, deal with the frontline, then the other minions, but if there are multiple FL's, then your 50-50 will happen for those. Got it.