I agree that Johnson noise is independent of the material. Some of the noise power may generate flicker noise but the total power in frequency unrestricted systems may be the same. A noisy resistor may shift in resistance value. I agree that the noise power of a group of resistors always equals that of a single equivalent resistor.
The I / V characteristic of diodes are sharper for smaller diodes.
The junction capacitance, a performance spoiler, is smaller for a smaller junction area.
In a matched impedance, half the current and half the voltage of the source is seen in the load ( 1 / 4 ). This is kTB.
The predominance of one polarity in many diodes feeding one load breaks the equivalence so many diodes can send many times 1 / 2 kTB watts times the rectification efficiency to the load, overwhelming it.
I don't think nature is infinitely insistent in supporting the second law.
Aloha, Charlie
