Not only does it come after a few more triode stages in Bassmans and Marshalls, but it also comes after a cathode follower stage, which drives the tone circuitry with low impedance. The BF/SF stuff is plate loaded, which can kind of skew the intended results. Interesting aside (IMO) regarding plate loaded tone stacks - it's my understanding that you have to basically look at the slope resistor as if it's in parallel with your plate resistance. So in the case of folks who try to 'Marshall'ize' a BF/SF tone stack, they're getting it wrong by changing the slope resistor, since you've actually got ~50K if using the original BF/SF value of 100K for the slope resistor itself. Point being that changing it to 56K, like in the Bassman, doesn't really work the same way. ...And that's why the Trainwreck stuff probably kept the BF/Fender slope resistor of 100K, despite swapping out the caps and pots for Marshall'ish values (Trainwreck amps all had plate loaded tone stacks, in between V1A and V1B, TTBOMK).