I wouldn't. If you mix it up it'd be all uniform, and becoming boring after a few bites. Whereas if it's separated, you could alternate between the tofu, the bok choy, or mix em up, alter the ratio of tofu-bok choy, or even just have the vermicelli on its own with the gravy, or maybe introduce a hot sauce later on, or add some seasoning like togarashi. Why make food boring when it can be fun and interesting? :)