When it comes to picturing the movers and shakers of Henry VIII ’s court, historians owe much to Hans Holbein and his preparatory sketches for noble portraits. Even still, discerning who is who can be something of a muddle. Of the 85 drawings in the royal collection at Windsor Castle , only 30 have been firmly tied down, with many resting on 18th-century inscriptions that claim to copy unverified or long-lost sources. As the director of London’s National Portrait Gallery put it more than a century ago, the identifications remain “open to question.” A new study has put A.I. on the case through a model developed by researchers at the University of Bradford , one well-tuned to identify a sitter’s bone architecture, proportional relationships, and geometric features. The model previously identified de Brécy Tondo as a forgotten Raphael painting and may now have name-checked two figures from Holbein’s drawings.…