I'm not so sure Soma and Megumi would be overly compatible. Megumi would never drive Soma forward, or anywhere at all. She would be simply satisfied with anything like the Yamato Nadeshiko she is (which would be no good for Soma, who already foolishly thought his old man's restaurant was all there is to the world of cooking). As much I hate Erina for being such a bitch, even she would be better than Megumi if Soma can break her stupid, false pride.