The easiest way to sort out the 2 'difficult' members who want 'morning slots only' is for them to take any 1 morning slot, then the first available afternoon slot.
Otherwise 2 members have to stand around all morning before seeing any track activity.
Unless there are any volunteers.......to sell £££££ their morning slots
to HongKongfooi or Scooby_Greg.
C.J or Charlie could exchange one of their morning slot for an afternoon slot, but I'll leave that for HongKongfooi or Scooby_Greg to arrange for themselves.