Ahah, thats more ... dissasociative personality disorder, split personality, multiple personality.

Schizophrenics have other voices in their head, but they treat and experience them as alien, not them, they're often antagonistic toward the other 'people', in there, get angry that they can't not hear from them.

DPD?

Such people usually view themselves as essentially a container for multiple 'people', whom they all usually do view as 'themself'... they just have multiple 'themselves', that they would actually tell you can all work together to achieve something.

“Together, I we can beat schizophrenia!”

fixed that for, uh, us, maybe?