So, the first castle wasn't built in Britain until 1051, and that was by French builders, and the trend for building them was really kicked off by the Normans (initially motte and bailey style, but stone castles followed less than a decade after the conquest). Prior to that, British fortified buildings were instead either reoccupied Iron Age hill-forts, occasional repurposed Roman forts, or buildings constructed in the image of one of those. (I assume the story is similar throughout Europe, but I don't know the details for other locations)
So, whether the flip happens automatically at a certain date, or when a mainland culture first starts owning land in the isles, or if individual holdings flip upon having their fortifications upgraded, maybe there could be two 'castle' graphics? An early medieval one that's a hill-fort and a high medieval one that's a stone castle?
So, whether the flip happens automatically at a certain date, or when a mainland culture first starts owning land in the isles, or if individual holdings flip upon having their fortifications upgraded, maybe there could be two 'castle' graphics? An early medieval one that's a hill-fort and a high medieval one that's a stone castle?