I know what you're trying to say, but you're still wanting to compare apples to oranges. (Even tho the difficulty rating percentage multiplier gives the impression of evening things out... )
What you want to let us know is what dictator you're using. (Or if it's a modified one, and if so, what attributes are you using.)
For example, if you have 'Booze Baron' on, you're gonna have a heck of a better score if you go for sugar/rum than someone who doesn't have that on, even tho the difficulty ratings might be the same. (Yes, I KNOW I'm being Captain Obvious, but work with me here...
And I use Lou Bega as my dictator, but the money doesn't roooool in until half way thru, since a big chunk of it is from nightclub residuals. (You need electricity for the nightclub, and once you have the power plants going, the TV Stations, and the Radio Stations and the Luxury Hotels, and WOO HOO! THE MONEY ROOOOOLS IN! Sorry, I digress...)
With the island that I keep playing (and playing, and playing...), I'm not gonna be happy until I get 2000 points, and I'm running at a 45% difficulty, with a fairly flat island, but the economy and the political stability are on almost full tilt. (I think the stability is one notch below 'Keep the jet gassed up' and the economic difficulty is maxxed out.)
And with a different island setup, (higher elevations, more minerals, easier settings, 'kinder' dictator) I could have the exact same difficulty rating, but an easier time...
Apples and oranges...