Do some research if you plan to use an oil that is not OEM. Make sure the oil meets the manufacturer's recommendation. We see a lot of hydraulic problems related to cheap "just as good" hy oil in our shop. Problems such as brake delamination, wet clutch failure due to heat, hy pump under performance, (low flow, low pressure, premature pump failure). Granted these are not scientific lab experiments but when you see problem after problem and tractor after tractor with hy issues and cheap box store oil you can't help blaming the oil. Heres a John Deere hy oil page to get you started on the research.
https://jdparts.deere.com/partsmkt/document/english/pmac/4968_fb_HyGardsTransmissionHydraulic.htm