`Module#<=` is a good idea :+1:, but I'm worry about the evaluation order.

If there are multiple candidates in scopes.keys (e.g. scope is EntriesController, and scopes.keys include ApplicationConttroller & EntriesController), I think the younger(=EntriesController) should be selected as the target. Because scopes.keys will not be sorted by their parental relationship, the target might not be an expected value.