I do something kinda similar with Hubitat. I have 3 valve sections; 1 in the backyard with 4 valves, another on the other side of the backyard with 3 valves, and 2 valves in the front. I setup the Rachio controller to control directly the 4 valves. Then installed Zooz Z-wave relay controllers at the other two stations to control those valves. Hubitat has a native Rachio driver, so I created rules to control the other stations. When Rachio turns on a specific zone, Hubitat will command that relay to trigger that zone. I hope that makes sense.
I’m sure you can do something similar with HA.