Pete there are two purposes for incorporating resistance in the secondary circuit.
To reduce erosion at the gap (& the distributor cap). This is said to be in the order of 1,000 - 4,000 ohms, but is not sufficient to reduce RFI. To suppress RFI 10,000 - 20,000 ohms is needed.
Driver Training (All Arms) Vol II "Contrary to popular belief held in some quarters, they [resistors] do not affect the performance of an engine in any way. In fact, in some engines, they improve the cold starting"
I did some experiments to measure the current flowing through the secondary circuit & found it to be very low. I think the introduction of 10,000 ohms only reduced the HT by 7 volts.
The thing to bear in mind with the voltage for the primary circuit, provided the battery is fully charged, that this voltage is just to build up the magnetic field so it can collapse & produce a back EMF to be stepped up by the coil secondary winding. The equivalent 12v coil the HT output would be of similar strength. Admittedly a load from the starter motor will reduce the energising voltage a bit but it is not necessary for the coil to be 100% saturated with magnetism to give a satisfactory output.
Have you still got the reference to that article?