Having read this thread and been thinking overnight I am going to put some thoughts together.
I can see that forming teams is a great way of increasing the challenge as well as a specific start time. With this in mind, the thoughts of teams got me thinking that if we are going to have teams of 4 then maybe 2 of the scores that count should come from B and C. Such as either B and a C or two Cís.
This might be controversial but I think it would encourage the teams, in general, to become more even. Some clubs may not have AA or A grades within them and by then having to go against teams that are made up of those higher grades it would possibly discourage shooters from becoming part of a team. Not everyone can attend the shoots with work and personal commitments, so another thought is having a pool of say 8 people named for that team for the season. The other point is that some clubs may not be able to field even 4 and so the region should allow shooters from other clubs to join that team.
Shotgun start time of 10-30am would allow for clubs that are travelling from the extreme reaches of the region to reach the clubs at the other extremes and any traffic or weather conditions that arise during the travel to the round. Also any issues with the course can be identified and corrected beforehand which should reduce the number of whistles. With on average of 40 people attending each event the round should still finish by 1pm (2 shooters per lane taking a total of 6 minutes to complete each lane = 120mins). If more than 40 then the extras can either be on feed on lanes or make 3 on the earlier lanes.
The shoots should still be open to all those that wish to attend as Winter leagues are sometimes the first taste of competition for new club shooters.