In this artwork, how is the Further Attributions discussed?
In 2019, John Vedder Edwards pointed out that the Rothschild bronzes are composed in an "open profile," with their arms fully extended. This, Edwards argues, is in direct contravention of Michelangelo's principle of organizing his sculptural figures in a classic "closed profile" with the arms and legs drawn tightly in  toward the body. Edwards argues that Michelangelo took to heart the instruction of early Renaissance sculptor Donatello that "a sculpture should be able to be rolled down a hill and have nothing break off." The presence of an "open profile," Edwards asserts, is definitive of a work being of an artist other than Michelangelo. Edwards does suggest that it is not impossible that Michelangelo may have aided Sangallo with the modelling of the torsos of the original wax or clay figures, however there is no evidence to suggest that this must be so. It should be borne in mind, however, that the "closed profile" was the result of Michelangelo's conceiving each of his marble sculptures from single blocks whose excavation, rough hewing and transport he mostly oversaw. In a sonnet for Vittoria Colonna written around 1538-41/44, Michelangelo wrote, "The greatest artist does not have any concept which a single piece of marble does not itself contain within its excess." The tensile strength of bronze sculpture, deriving from a cast of a model, allowed compositions impossible or difficult in marble, such as the raised arms of the panther riders, and witnessed in the almost certainly raised arm of Michelangelo's Pope Julius II in bronze, made in 1508 but destroyed only a few years later. 
In 2020, Michael Riddick argued that the Rothschild bronzes are more likely to be the work of Francesco da Sangallo, the protégé of Michelangelo and son of Giuliano da Sangallo who mentored Michelangelo in architecture.
Francesco da Sangallo Michelangelo Vittoria Colonna Giuliano da Sangallo