In the 2nd drawing, it all depends on the size of the supply piping from the main meter, and the gpm capabability of the meter and it's feed from the street. If the supply is limited, then if either house draws too many gpm, or if the total gpm to both houses is too high, the pressure at that point where they tie together will drop. 2nd house also has the issue of lenght/size of its supply line. By the way. both houses will then experience pressure drop when the irrigation is running.
35 PSI is a relatively low supply pressure, at least by standards around here. There is a good chance that both houses will have issues. I don't know how you support an extensive irrigation system off of this, unless the house supply is large and delivers large gpm/