The balancers could literally be part of the plan in your bus. Maybe you branch off a line of iron and two of copper to a green circuit plant that is then coming back onto the bus and being used downstream by both modules and red circuits. You know that for the next few hours those lines will be completely consumed by the number of modules you’ll be creating but after that your red circuit production will be able to go full speed and feed electric engines for robots. Your argument seems to be that you should just have enough lines to do both at full speed. That’s reasonable for the late game, but earlier the needs of your production are variable.