I think what you have for the majority of the circle bonuses works well. From what I've seen, most the bonus follow a pattern: <=20 territories in the bonus, bonus is equal to 60% the number of territories in the bonus; >20 territories, bonus is 25% the number of territories.
I think you should apply this logic to the rest of your circle bonuses, but use this key:
*1st tier bonus=60% number of territories inside, ex. ABC Islands is a 1st tier bonus containing 3 territories, so it should be worth 2
*2nd tier bonus=50%, ex. Dutch Antilles is a 2nd tier bonus, cause it contains 1st tier: ABC Islands, Dutch Antilles has 6 territories, so it should be worth 3
*3rd tier bonus=40%, ex. Leeward Islands is a 3rd tier bonus, cause it contains 2nd tier: Dutch Antilles, Leeward Islands has 14 territories, so it should be worth 6
*4th tier bonus=30%, ex. Lesser Antilles is a 4th tier bonus, cause it contains 3rd tier: Leeward Islands, Lesser Antilles has 20 territories, so it should be worth 6
*5th tier bonus=20%, ex. The Caribbean is a 5th tier bonus, cause it contains 4th tier: Lesser Antilles, The Caribbean has 30 territories, so it should be worth 6
*6th tier bonus=10%, ex. West Indies is a 6th tier bonus, cause it contains 5th tier: The Caribbean, West Indies has 34 territories, so it should be worth 3
*7th tier and after=5%, don't go lower than making a circle bonus worth 5% of the territories.
Use these rules to help apply the key:
If a bonus contains parts of other bonuses, apply this key in order of territory count.
If a bonus contains more than one bonus, apply the highest tier it can get.
Ex. If there's 3 overlapping tier 1 bonuses that all share at least 1 territory, the one with the lowest territory count stays a tier 1, the next lowest becomes a tier 2, and the highest becomes a tier 3, but if that tier 3 overlaps part of a separate tier 5 bonus that has less territories than the tier 3, then that tier 3 becomes a tier 6.
With each territory being worth 1, the solid square bonuses, those would balance out the bonus drops for the higher tier bonuses.
Edited 10/15/2020 19:53:13