I would suggest to put a tank in front of Tholin so may Leon for the increase of physical attack, Drago, or Elric. You could then choose Leah, Jasmine and Gizmo
Front line: Leon | Tholin
Middle: Leah | Jasmine
If you want and if your Tholin is really strong and can keep himself alive, you can choose to drop Leon and add in Garrick; however, I think Leon is still a good choice. Make sure Leon is really strong, though, so he doesn't die quickly.