Strategies:-
Since Slanths, Crudgins and Roukes can be phased, its advisable to have 1 Roc/Orbus to allow them to escape incase an enemy is chasing after them. Always phase the most damaged Slanth/Crudgin/Rouke away so that the enemy will have to aim others. Also, its advisable that you have your Orbus in a save place, away from the battle.