you’re not missing anything, it’s an unhinged tradeoff that you do because you need to conserve copper for brass casings because nazis are in calais, there’s zero reason to do this today. apparently it’s still allowed in uk for some unthinkable reason but i haven’t heard of it anywhere else. yes, single fuse *per ring is used, rated at double what it would be in star/radial circuit

you don’t even need a fault, sufficient asymmetry in ring geometry or load distribution already will cause this problem