In terms of P/N/P layering I believe (from my limited understanding) that what you're saying is generally true. However, given two diodes you can't make a transistor, so it is not equivalent to say that a transistor is just two diodes. Especially at this ultimate scale, proving a diode is not the same as proving a transistor. The mechanism of semi-conductivity is not the same at 0.5nm as it is at 14nm.