True but considering the fact that this Jubi that Obito absorbed was a minimally aware Jubi not fully concious entity. A Jubi overwhelmed Obito should be theoretically a blank slate type seen in other manga ....Look at the Manga again Obito is not quiet they're Mentally,the sensations and things He is now seeing and experiencing are over welling Him, look at the way He says His own Name. He look child like.
For now yes ...... But Obito may manage to become the dominant one if he is given enough time.Indeed, it's an "it" not a "he"