Most of the group were unable to keep up with Quinn, with the exception of Peter somewhat, and they all knew that, but they had decided to follow him anyway. Even though Quinn was leaps and bounds ahead of him in strength, Peter knew that at times there could be trickery involved, especially with all this celestial talk Quinn had told him about.
Still, when seeing him dash ahead into the group of Chained, Peter knew that he was able to deal with it. Even when Quinn had missed, he wasn't worried and seeing him summon his blood aura; it looked like Quinn had control of the situation.
After all, Quinn was only using the appropriate power needed to crush these fools. In fact, Peter believed when summoning the 1000 blood swords, he was perhaps using too much power.