As far as I have read, there's never been anything mentioned about the order being for some purpose, that the Buddha put them in a specific order.
However it is often mentioned that the first one is the first one for specific reason. And that is because Generosity is the easiest of all the Paramis to do. It is a Parami even bad people can do. They can be generous to their family and friends. In that way Generosity might be first because it is the easiest, but as to others in that order there is nothing that I know about.