Maybe you are right Scapa ,time will tell,however alot will depend on the trips that move to MF.As yet we know very little about the longhaul destinations that will be put on to the Mid Fleet ,or the length of the trips,you cannot choose to earn the big money if the potential to do so does not exist.
I would expect that most crew would bid for longhaul because 1/ they see it as more exciting and 2/ it bringing in more money.If most do this there will be very little to go around especially at the start.