I am against mixing types. In another industry, aviation, back in the late 70's there was a failure of grease when two non-compatible greases were mixed and lost all structure that made it grease. Lost an aircraft as a result.
I know this is a tractor not an airplane but the possibility of loss of properties due to non compatible fluids is the same. Of course you are talking to someone that when he changes the hyd fluid in his machines he changes the remnants of the fluid that is in the attachments by flushing them as well. It took a bit over 33 percent more fluid to do that but that would have been 33% dirty fluid that would have circulated if it had not been done.
Your choice but ...................:thumbdown: