Reasons I think the Circus should've been spared and just moved in with Ciel;

Just imagine the Noah's Ark Circus members having their first warm showers, imagine how good it would feel for them. Imagine the first time they laid down on a feathery soft bed, falling asleep almost immediately because it's so freaking comfortable. Imagine their stomachs growling just when they smell nice, warm, fresh food. And they don't have to race anyone to get to it, because there's plenty. Imagine Joker, Beast, and Dagger being able to get new prosthetics that aren't made out of human bone.

Imagine how happy they'd all be.