Capella

Capella is one of the classical Behenian stars directly preserved in the local corpus. That gives us a reliable starting point: define the materia, define the operation, and avoid loading the page with unsupported modern symbolism. (Hess and Warnock, De Quindecim Stellis; Agrippa, Three Books, Book II, ch. 47)

Warnock's summary of the Bodleian material and Agrippa's list pair Capella with sapphire and horehound, with Agrippa adding mint, mugwort, and mandrake. The operation preserved there is also unusually concrete: favor, honor, elevation before rulers, relief of tooth pain, and broader medicinal usefulness. That is why Capella fits naturally in this section's overlap between stellar magic and medical support. (Warnock, Fixed Star, Sign and Constellation Magic; Agrippa, Three Books, Book I and Book II, ch. 47)

Ptolemy gives the bright stars of Auriga a Mars-and-Mercury nature, which helps explain Capella's combination of activity and skill. Brady's concise modern keyword, the need for independence, can be kept as a later interpretive gloss, but the strongest local evidence is still the older combination of favor, courtly acceptance, and healing help. (Ptolemy, Tetrabiblos, Book I, ch. 9; Brady, Brady's Book of Fixed Stars)

So the safest summary is a practical one: Capella is a Behenian star for honorable reception, technical usefulness, and selected medicinal support, not an excuse for generic helper archetypes.