According to Mr. Gary Bonnell, when one soul incarnate into the material body, at least another soul is needed to ignite a plasma-etheric energy which can let the soul walk into the heart or thymus gland.
In it, yes indeed, two souls are, at least, connected in the incarnation process; however, after this process, another soul can leave whereever or whenever it wants.
These two souls can be put as so-called "Twin Souls"?
Well, my impression tells they are not.
Yes, they are cooperating, however, they are, in the first place, not limited to the specific souls: they are totally unique one being, or so-called "Triadic Being."