Because of the distrust Nathan sowed into the enemy's ranks, everyone was a bit skeptical about working with Rudeus.
The students ended up dividing into three groups. The first group would be those who wanted to suck up to Rudeus by trusting him. The second group simply wanted to fight by themselves, not trusting anyone except for their pair.
The last problem was the one problematic for August. They actually made a coalition to take down both the Nathan-Selena pair and the August-Rudeus pair. It was as if they had been betrayed by them and just wanted to take the top spot for themselves.
Their ambition had halted Rudeus' progress from taking over the event.
Rudeus did his best to convince them, but Nathan manipulated them so well with his status. By turning into a victim himself, he managed to provoke everyone's empathy.
Although no one wanted to side with him and Selena, it was enough to buy them time.