I would imagine that you need to take into consideration the difference in arena revenue too.
Do you expect that you can make more each week on average going 22-0 in Italy II.I with a full house compared to a Japan II.I series?
If the palace has the same size,with the same prices for the seats,the attendence is EXACTLY the same,and so the arena revenue
This mechanism was thought by BBs to allow the users all over the world to reach the same level,no matter the country they were in
And this mechanism would be fair,but the weak point of this system is that not in every country you have to spend the same money to reach a certain goal(win II div,reach the playoff in a III div and so on)