I like that Dracro is keeping up with Ginko, it shows that he is in fact a strong top class hero.
Him struggling with her is down to a few reasons I think:
1: He's trying to arrest her not kill her, she has no such impediment.
2: He's not as used to fighting humans as she is, Ginko has far more experience there.
3: He's distracted due to trying to figure out what's happening and who/what Ginko is.
All in all I think if they fought 1v1 fairly it would be a bit closer a fight than in this chapter.