The original B1 molds were really detailed for their time and hold up perfectly well imo. They changed one of the arms, and I think that's about all they needed. The split legs would be great in theory, but with how thin they are it would likely result in very weak joints. Any attempt to match the style of skeletons would make them very wide. And frankly, I don't think they should be making any major updates that makes the two groups of figures difficult to have in the same mocs/arrays when there's so little to gain.