Tradition assigned the commentaries to Confucius, and the ascription did real work: it is what made a divination manual a classic that a scholar could study without embarrassment. It was not accepted indefinitely. A Song dynasty scholar argued on internal grounds that the great commentary could not be by one hand and could not be Confucius's, pointing to inconsistencies and to passages that quote as though from elsewhere, and the doubt has been part of the discussion ever since.
Modern scholarship places the commentaries across several hands and a long period, in the Warring States and early Han, and reads them as the deposit of a developing tradition of interpretation rather than the work of a single author or school. The strongest evidence arrived in the twentieth century from a tomb. Silk manuscripts recovered there include a version of the classic with commentaries that are not the ones transmitted, overlapping only partly with the received set. That shows the wings were still an open collection at the time the tomb was sealed, and that what became the standard ten was one selection among others. The received grouping is therefore a decision taken at some point in the Han rather than an inheritance from the classic's own formation.