It depends on what your current troop faction is (temple or church). Because bonuses from troop type training research give a big help to your army. For temple, go for the offensive types (go for aoe type troops if possible) since SR Honda has atk and def boost from her first skill (elite marksman or elite black rider). If church, it can be elite artillery, elite samurai or elite swordsman. But it all depends to you XD
Don't forget to unlock and finish the hidden dungeons on chapter 1 and chapter 2 so that you would have extra or reserved troop types to consider once your army would change.