Everything is descending one way or another from the sun and moon, and each will have their own lineages, although they are never in conflict and always life long friends such as Venerable Sāriputta and MahaMoggallāna , its far to complex to trace all of them out and not one person will posses knowledge of the lineages, or maybe only a Buddha, its a bit like trying to count all the streams in the world. This will not just be limited to India or the ancient map of Bharata Varsha.
Without writing anything off its unlikely that the human race descends from the planet moon, that maybe taking it to literally....
Sun surya represents light~ joyti Illumnation and moon represents sound~ shabda, everything in creation is manifestation and mixing of sound and light in one way or another, these are powers of brahman according to vedic texts, and their expansions are unlimited. Sun represents the dharma vehicles of illumination and organised knowledge, Sāriputta was the dharma vessel of the organised dharma teachings which bring illumination joyti , there was none to match him in terms of knowing the dharma teachings second to Buddha, maybe only Mahākassapa aka kasyapa Muni, one of the saptarishis, he is kinda of in a league of his own none can excel him except obviously Buddha. As far as I understand Sāriputta was the founder of the monastic traditions and learning through the suttas. veda is combination of sound and light, shabda and joyti, sun and moon, surya deva and chandra deva.
Moon is more lucid and not so technical, MahaMoggallāna was more of a mystic, he was teaching through mind sciences and siddhis, a lot of his lineages are still held within yogic traditions of the Himalayas such as nath sampradayas of Goraknath and many others stull living today, Guru Goraknath was a disciple of Matsyendranath. There is no start or end of Nath sampradaya and they transcend time and space, kala and akash.
Sun and moon also have functions in the brain, left side is the empirical function and right side is the creative function. Some people maybe more left or right sided and need different ways to learn, so each of the lineages coming from sun and moon will have pure ways in their own rights.
There are a lot of interesting things even if learned technically about these things. The sapta rishis 7 seers and how they are connected to the 7 ancient universities of India, Nalanda was just one of them and how they are related to all phenomenon and the transcedent.
For sure there is a direct link between the esoteric and exoteric, although all creative manifested phenomenon that we experience will have subtle cause which then manifest as final result in the outer experience and larger universe, but its all aligned, we may not be aware of due our minds not being refined and enlightened enough.
Some people often ask why the Theravada tradition lacks in esoteric Knowledge, it doesn't , its all in their but a bit more hidden, vac comes in 4 levels.
In the upper dharmas ar higher dharmas things become more unified, the saints and rishis, buddhas and bodhisattvas are not fighting, even in the subtle realms they maybe some flux or duality, but it less or more refined and only serves to promote direct insight into Truth.
So much to rediscover. There is a very mystical language and communication going in the suttas, personally I only have a few basic simple texts that I have for daily study and reflection and practice, in the pali suttas the one I know and stick to the most is kevatta sutta. If one suttas is understood, they are all understood, quality over quantity.
Purniman full moon observances are followed very closely in Theravada because of the direct effect on the mind in meditation, if one is observant then the mind certainly goes into different mode around the moon time, moon is very auspicious.
Its all connected, were dealing with vast lineages over thousand and thousands of years that are deeply connected, it transcends any dogma or litery study, our duty as individuals is just to cultivate the mind and serve society and others to our best capacity. Dharma cultivation without seva or service will slow down the ripening process and its advised find some wise association.
This is just a quick response answer and I will be off for a few days and maybe some other things can be explored in more details and I would welcome any other insights in line with dharma connections to other paths.
Just for reflection and to promote more study how ever one does that into sound and light.