Considering this case, in which we don't expect the items to be very many (mostly 1-2, but can get to 5-6 tops, and there can only be one favorite: The order of the items is the one in which they have been created.
Version A establishes a fixed spot where you can always find your default and could also use direct manipulation to set the default, while version B keeps the consistency of the positioning of items in the interface.
Which one is a better practice?
p.s. this case is in the context of a 'preferences' section, where the user would come to change default settings.