The artist produced several drawings that year with similar content and title, just experimenting with the figures and postures used. An armiger is essentially someone who has the right to bear a coat of arms and was used more so in centuries past. There is little about this drawing that can be described as grand or hereditary, with the nude models reduced to a compromising position. Michelangelo was famously forced to cover up his extensive set of figures in the Sistine Chapel after disagreements over their suitability for this traditional venue.
There is an abrupt crop to this drawing which suggests that it may have been part of a larger sketch which was cut out to form this. That may have been because elements of the larger piece were damaged or simply not to the artist's satisfaction.
The Museo Nazionale di Capodimonte in Naples has a fine collection besides that Michelangelo drawing. Find also there the likes of Crucifixion by Masaccio, The Misanthrope by Pieter Bruegel the Elder, Madonna and Child and Two Angels by Sandro Botticelli, The Flagellation by Caravaggio and Mary Magdalena by Titian. This institution has the most significant collection of Neapolitan painting and decorative art alongside its collection of work from other members of the Renaissance, be it from other papal states or elsewhere in Europe.