I think 9 out of the 12 teams from just three countries is bit over the top.
That will mean half the Aus Dom teams, half the SA dom teams, and 3/8 of the IND Dom teams.
3/8 IND Dom teams is alright, but I think two should be the maximum from Aus and SA as they each only have 6 teams altogether.
The defending champions should have an automatic spot each season, 3 SA teams ain't ideal but they are the host and if we want this concept to continue then having 3 home teams would help that case. This is a special case for it since England pulled out. In future it should be 2 from each country plus defending champions.