Deve,
With a given voltage, the current flow of a circuit depends on the cumulative resistance of the circuit which would be the sum of the resistance of the accessory (i.e. motor), reducer (which is a resistor), switch (and it's associated resistors in this case), wires, ground, etc. It doesn't matter where the reducer is in the circuit.
Also, I don't understand your reference to resistor wattage. I thought resistors were rated by Ohms. Of course, resistors produce heat (watts) when in use but this would depend on the voltage.
In lieu of a test bench I consulted an engineer and an electronics tech whose hobby is rebuilding auto tube radios and auto gauges.
Perhaps someone can clarify for me where I am in error. I, too am getting older and relying on classes I took 40+ years ago.
Regards
Kent