If this light rail is to service Caulfield, Chadstone and Monash Clayton before heading to Rowville, then I don't see the point in running down North Rd at all. Just go straight down Princes Hwy, and then turn into Wellington Rd and off you go.
North Rd is just a needless diversion that would add an unwanted increase in travel times.
Keep it as a simple, fast, high frequency, direct route with stops spaced appropriately. That is how you will get people to leave their cars at home.