Hey there, I'm trying to deepen my understanding of rules and game design. I've noticed that design has mostly backed away from different card types sharing subtypes. Instants and sorceries share Trap and Arcane subtypes, which seems to be an acceptable overlap even though they haven't appeared on new cards in quite a while. Tribal is a different ball of wax, and a lot of the problems with it seemed to come from putting creature types on instants and sorceries. As it stands, Artifact and Enchantments don't share any subtypes despite having a lot of the same play effects (free-standing permanents that change game rules, permanents that attach to other permanents to modify them). Is there a rules or play roadblock to keep artifacts and enchantments from sharing types? Artifact-Auras could cause trouble, but could Enchantment- Equipment cards exist? It looks like Cartouche would not only work on an artifact, but they've actually been depicted as artifacts. While there's maybe a "specialness" to having those remain distinct, it feels like it would be easy for most players to figure those overlaps without any additional preparation.