is "anderledes" instead " forskellige" valid here ?
I don't think so.
I remember someone asking on the difference between anderledes and forskellige and they answered that the first is different/special/out of the norm while the second is simply not the same.
Exactly ... if you used "anderledes" in this sentence, it would imply that both countries are using something different than the rest of the countries in the world.
Det måtte være: De to mennesker bruger forskellige valutaer. Læs den østrigske skole for flere informationer og spørge mig, så vi kan prøver at have en debat om økonomi i dansk.