This subject came up when I did my 737-200 course in Seattle in 1977.
It is correct to say that full manual breaking is greater than Max auto brake but it would be quite wrong to say that it must, therefore, be used in preference to Max autobrake as it completely misses the human factor.
With due respect
Safety Pee, your statement:
The best possible deceleration – minimum landing distance, is with max manual braking and reverse thrust.
is true in theory only.
If we think the flapless landing process through, using Max auto brake, the brakes will activate as soon as the system agrees the aircraft is on the ground. At this same point, should Max auto brake
not have be selected, the pilot is lowering the nose, selecting reverse, keeping straight and trying to apply max braking through the pedals, an unfamiliar exercise in coordination that is something we don't normally get the chance to do very much, (try it in your chair whilst reading this!). More importantly try it in the SIM the next time, you will be very hard pressed to beat the
initial braking achievements of Max Auto brake, even after several practices.
The consensus at Boeing was, let the Max Auto brake do it's job ASAP whilst the pilot completes the touch down then, by all means, go for max manual breaking, when the pilot is not trying to do a few other things at the same time. Do remember that the Boeing numbers and procedures are based on the average line pilot, not the TRE/SIM instructor.