The guessing game for me is which routes will be operated by the based aircraft and why!
I assume it only makes sense to have a based aircraft for a limited number of routes they want to operate to non-bases that can't easily fit into a w pattern either operationally in a convenient manner or because operating the flights at particular times non-based aircraft can't do is strongly beneficial.
Given that they don't really do business routes (or maybe they want start doing so?) timing isn't an issue (and perhaps giving people till later in the morning to get to Luton is even an advantage, seeing as it's not the easiest airport to get to?).