As people will realistically only need to charge about once a week on average, about a third of the spaces will probably do. Or you could put slow chargers in every space in some cases (e.g. work car parks where people park all day). It'd also be possible to have electronic control of such chargers - if the grid connection won't allow all to charge at once, have a socket in every space (thus no fighting for one) but rotate the load.
My own academic research (system decarbonisation is my field after all!) would indicate that the more chargers the better.
The ultimate objective would be to engrain a habit of plugging in the electric car whenever possible, so that electric cars are available to absorb gluts of renewable electricity whenever they appear.
Especially in the summer when a future renewable system will likely be flooded with electricity around lunchtime.
That would tend to reduce overall system costs, and thus the average price that electricity must ultimately be sold at.
I think the overall objective would be to put a car charger on every space, even if the current limitation functionality of the charging standard is required.
There is no need to rotate the load, as electric cars are required to obey a PWM signal on one of the pins of the common charging plug standards and throttle current draw accordingly. You can smoothly throttle charging load all the way down to the low value of 1.38kW if needed, and have it dynamically respond to the number of cars actually charging at any given time, with no stop-starting.