Compass Carburettor never needed his powers as the God of Humanity to deal with Arnark. Even as a mortal, he was long since fully equipped to deal with the latter.
But being the God of Humanity resulted in all the important characters of the world paying attention to him, increasing his weight to the world. As a result, Lore and Tell-Tale personally focused on him too.
This allowed him to get a larger audience to display Arnark's maniacal dance moves. The dude was losing his shit by now, having been at it for a few days already.
The fact that Peddler would sell tickets to the event, making Saints gather to spectate, the region of the fight, the actions of the divine beasts, the various fights, everything seemed to be well within Compass Carburettor's calculations.