Don’t the trads have drum brakes at the rear?
Yes - and all that's needed. ARP4 was the only road car exception.
My mid 80`s +8 Trad has two pot callipers, drums on the rear, no servo or ABS, has good firm pedal action to the extent that I can lock the wheels, which I know is not the best possible braking action. When multi-pot calipers became available for Mogs on the aftermarket, I imagined that they might just equate to locking the wheels with less pedal pressure, a subject Colin AKA spanner juggler engaged in some years back.. I have memory issues, though think Colin suggested that more pots in the callipers equated to more pedal "feel" in the braking process, though how that might work in panic braking... Hmm..?