If you read Enneagram, in particular Don Riso and Russ Hudson, though it isn't as common, you can have "two wings", and even with one wing, that wing may be close to the Basic Personality.I met so many people in real life or online having the characteristics of more than one types, and their tendencies toaards the types are very near.
The meaning of knowing what your type is to understand yourself more, discover your strengths and weakness, find out what kind of people match you, know what job you are suitable to do...
But those people who show characteristics of more than one types often have strengths and weakness, characteristics of more than one type. Why can't they be two types?
I know this us against the MBTI theory, but remember, MBTI is not proved. Why can't we have our own theory to it?
MBTI is just a theory, not perfect. I prefer Enneagram as detailed by Riso and Hudson--and I've studied their work in print--not picked up odd references taken out of context.
Next, Enneagram Nine is the most likely to have medical model Multiple Personality Disorder now usually referred to as DID.
My MBTI is most likely INFJ; my Socionics is INTp; my enneagram is trickier but I'd zero in on 6w5. My cognitive functions based on Keys2Cognition gave me INFP.
Similar minds just gave me ISFJ.
That's it for now.