I did set up the two zones exactly the same and have had installed for a few weeks now and the two zones seem to follow each other exactly so I think it should work okay. One had only slightly more in/hr than the other when measured by the city water meter so I just averaged them and set for both of them.
Thanks for all the help this was really good.
P.S. going through the actual measurements, I found my backyard zone default parameters from Rachio was almost 3X actual so I have been significantly under watering. In fact I am sure I have for many years even with my manual controller I used to have.