There’s definitely some subjectivity here. The way I see it is, not necessarily high gain, but more-so the effect is producing enough upper harmonics in a way that they are creating an audible dissonance.
I think the Driving Notion is a parallel drive on a JFET blend,
the "high" side seems to have small interstage caps and the bias is intentionally weird, near gated, + 100nF input cap = clang
the low side is pretty standard 2 2N222 stages + 1uf input cap = wool
Theres a passive EQ split happening with the input caps I think, the low side overpowers the high-side on the lower three strings, while the clang is much more prominent on the upper three
Thats the cool separation effect, I feel like those Sallen Key-filter style 2-3 band distortions designs have a similar feel, with how you isolate and have fine control over those upper harmonics
I can play Neo Soul chords through it and a cleaned up Harmonic Percolator, so there are definitely clang designs with much less gain...