I don't know of or have even heard of any temporary residents of Argentina who have the visa rentista or pensionado who pay taxes on their foreign income in Argentina. Someone who has temporary residency based on these categories may also have clients outside of Argentina who pay for some type of service, but I've never heard of anyone paying taxes on that "income" in Argentina, either.
I am a monotributista and have a rentista visa and my accountant here has always told me that I had to pay taxes on my worldwide income here i.e. also on income from foreign clients. I now have a permanent visa but this was also case with the temporary visa.