I don't think sorting is helpful here.

Given the typical blog count it's probably ok, but we could limit the results to the blog ID, since it's the only thing we want, see [-[NSFetchRequest setPropertiesToFetch:]](https://developer.apple.com/LIBRARY/IOS/documentation/Cocoa/Reference/CoreDataFramework/Classes/NSFetchRequest_Class/NSFetchRequest.html#//apple_ref/occ/instm/NSFetchRequest/setPropertiesToFetch:)