Is there really a difference in oil for air cooled and water cooled engines?

Yes,air cooled engines fluctuates in temperature, that depends on the outside air temp. Water cooled engines are subjected to coolant temp values,let say 175 - 200degrees Fahrenheit. Selection of oil viscousity depends on engine performance ie..high compression engine, and weather temperatures.Is there really a difference in oil for air cooled and water cooled engines?
Air cooled engines tend to run hotter than water cooled engines, so a higher viscosity oil is used. My airplane uses 50 weight.