* Steal a radio, you're stealing from a person.
* Run a Ponzi scheme, you're stealing from a group of people.
* Counterfeit a nation's currency, you are stealing from the people of that country.
So, to answer your question: Sure, counterfeiting is just theft.
And Hitler was just a killer.
Scale matters.
I think you got to the heart of the matter when you wrote "Scale matters". Murdering millions of people is a bigger deal than murdering one person. Theft of millions of dollars is worse than theft of one dollar. The problem I have is the distinction is made not based on scale but by the means of theft. I suppose the idea is that is is worse to steal one dollar each from a million people than a million dollars from one person, but I disagree with that conclusion.