I'm curious if you have any data to back this idea up. For instance, do you have an example of any human being who has fused a Real magnetic center alone? Or is it more a statement of, "I think it must be possible"?
Apologies for not getting back to you on this immediately.
I don't say that it's possible out of sentiment, but rather because it is my reasoned opinion. I cannot provide specific examples of people, as those who we would know about are those who would be known to others through dialogues and discussions of the topics they have mastered - hence, all historical examples of accomplished individuals that we know about are C influences (part of a school/network environment)
a priori.
The reason I think it is technically not impossible to reach the Esoteric Center without C influences is because all that is intrinsically necessary for one to access the Esoteric Center can be found in B influences. I explain this below.
The source of salvation comes from within, through the utmost discipline of the mind-body and purity of consciousness. A influences lead one nowhere, because they are not related to consciousness and provide no direction in searching for the Esoteric Center. They are entirely subject to the law of accident.
B influences are capable of reaching people on a conscious level, kindling the potential for its development in order to learn to distinguish A from B in the formation of the magnetic center. B influences also radiate from the Esoteric Center as a sort of magnetic field, so they are capable of providing some indirect direction to search for the Esoteric Center. B influences are subject to the law of accident only some of the time.
C influences offer an unbroken chain to the Esoteric Center, are full of consciousness, and are never subject to the law of accident.
If you compare two individuals, one with only access to B influences, and one with access to both B and C influences, it is plainly obvious that someone with C influences is receiving the things necessary for finding the Esoteric Center in much larger quantities than the person with only B influences. But in spite of the fact that they are in different quantities, there's nothing in C influences that is noticeably absent in B influences (both give direction; both create opportunities for greater consciousness; both offer a reprieve from the law of accident) and both, at least, they way there is between C and A influences. This is why I felt it was necessary to point out that, while those with C influences are much more capable of finding the Esoteric Center than B influences, it's not technically impossible the way it is for A influences.
Another reason for believing it is possible is due to mental monoism. Since the conscious substances that compose our souls all belong to the same macroscopic soul, that larger soul can attain unity and wholeness only through itself and no other (the intrinsic necessity of a "school" in this context would imply something existing outside the universe, which is a contradiction in terms).
In terms of practicality though, the subject might as well be treated as if it were impossible to graduate without a school, because getting by on the smaller quantities that B influences provide alone requires an extraordinary character rare in most people.
I hope I satisfied your questions and curiosity, anart. ;D