Using a single skeleton with a large number of skins and animations is a common approach in Spine, especially for projects like 2D RPG games where characters share animations. There is no hard limit on the number of skins or animations you can have in a single skeleton, but performance considerations should be taken into account. Having a large number of skins, such as 300, is feasible, but it may lead to increased complexity in managing the project and potential performance issues, especially during editing. To manage this, you can use techniques like grouping skins by archetypes or using skin bones to manage different features like capes or hair. Additionally, you can create skins at runtime to reduce the number of skins in the editor. It's important to ensure that your naming conventions are clear to avoid confusion when dealing with a large number of assets.