Everything has advantages and disadvantages. If you do them separately, you get to master each one. If you do them together you get to master the transitions. If you do them together on the other hand, like was said, each will try to go into the best territory. (Top, bottom, clinch, inside, outside, etc.) I would break up the class into 3 parts. A part standing, one part on the ground and one part both. Oh wait? How would the transition defense and offense would be worked on?