After a night of passionate sex, Andrew met up with Castor and Vala before they left. While Castor is the second most powerful fighting force at Andrew's disposal, he isn't worried about letting him go.
His safety was guaranteed within the Heavenly Palace and when he needed to go out, Oliver was always the one to accompany him, so sending Castor and Vala on a mission was not problematic for him.
In fact, he was more worried that something would happen to them in Calci since Castor was moderately recognized in the city and there was still that strange organization that had chased Castor's gang before.
According to what they knew, that organization was no longer in Calci, because they found what they were looking for, but Andrew couldn't stop worrying about his friend and girlfriend, but as he had said, if he stayed in the safe zone always, he will never get better.