I thought they wouldn't get there until it was already over. I'm not sure if Mako and Asami will be able to see the arena from where they are, but if so, they can race there for the climax. Truth be told I don't remember much from the attack except a Zeppelin. I don't think Amon even appeared, did he?

Holy crap I don't wanna watch Korra again lmao the first two seasons yo... last two, sure.