For a point of reference, my Model T has what has to be the simplest belt drive ever with only pulley to drive, which turns the fan. The factory belt is a leather strip, not rubber. There is no water pump, alternator, or anything else to turn in the front of the engine.

My beetle is almost as simple, one pulley that drives two accessories. It directly drives the generator pulley, and the generator shaft goes forward and drives the engine fan. Adjustment is the unique part on this one as the generator pulley is a V design in two halves, and you add or remove shims between the pulley halves to effectively increase or decrease the diameter of the pulley which adjusts belt tension.

Is this the kind of info you're looking for?