The enneagram trifix theory is missing a center: the soul center

[Samson]

Whence did you learn this, since you talk so authoritatively?

((The soul has no ego, as such it has no "personality type."))
I learned from many different sources. Many Enneagram authors emphasize the difference between personality (ego) and the Self (capital S) beyond ego, stating that one's personality type is about ego identification, not about soul. The soul occupies the Virtue of Essence. Each Enneagram type has a Virtue, and it is ego that leads us astray via the Passions of the types. This distinction is elemental to the study of the Enneagram.

((By definition, the soul is beyond this material world.))
The concept of the soul being beyond the material world is a rather universally accepted view on it. Doesn't mean that it is real, that's for you and each person to decide for themselves. There is the use of the world as synonymous for "person," but this interpretation has been falling out of fashion the last few decades (I blame the New Age movement). So I said that the soul is beyond this material world with some confidence, yes. I said it to contrast this with the 'worldly' nature of the body, the mind, and the heart, and to show that this is why "soul" shouldn't be a center.