Even if you could find a conclusive answer here, it might be outdated. There may have been changes since the guides were written. Trial and error would be the best suggestion. Keep adding or removing negative quality players till you are happy with the quality of opponents. If there are no changes and negative players no longer count in the draw, keep fewer strong players and a good mix of players below 3 stars to help manipulate. Just observe the top 100 associations team makeup closely, there will be workarounds we can work with.