With Leo heading off with the boys, Quinn was confident that any troubles they ran into, he would be able to deal with them, even more so if he was to go with them himself. Even if the vampires were against Quinn and his tenth leader family, Edward said it would be crazy for them to try something so soon right after the king made his verdict, so the boys were relatively safe from the others.
However, what Edward was unsure about was Leo himself. He didn't understand why the second Leo had said he would go with them, Quinn was calm about the fact that they would be going to a dangerous place. From the descriptions and stories he had heard, a place full of Wendigos and perhaps even more. If Quinn had asked him to go with the boys, then he would have done so as well, but instead Quinn said he wanted him here to help him with his other duties.
