If this is your opinion, then one assumes you have completely discounted the theory that the attractiveness of a UK deal to serve two airports was what brought them to MAG in the first place. Something you might want to explore with your sources in more detail
Its not necessarily my opinion, but, its not exactly a great position for MAN as a standalone unit to be waiting on STN. Would it have been a lot smoother had MAG not brought STN, its all speculation and we will never know.
My comment was purely aimed at the fact this is the first time MAN has 'relied' on another airport to get its flight also. Nothing more.