my house has 1/2 copper supply in backyard can I go up to 3/4 inch to supply vacuum breaker and valves im only running 4 to 5 heads per valve longest run is 30 feet
Don't rope yourself into a bad design by making assumptions. Better to have more smaller zones with good performance, than a lesser number of crappy zones. Your field plumbing can always be up-sized from the supply plumbing.