IMO
Your group stake is not really the best solution, just means the smallest block amount is the same for everyone, when it comes time to stake, everyone that does not manually combine has the same # and causes them to have a lot more orphans. They still need to recombine higher than your group stake setting to mint well, so not a good option since they still need to manually combine to avoid excessive orphans.
A Better option would be if you just quit splitting blocks below a certain number, this keeps everyone from having the same amount in their block number, and would be less orphans.