I think like zen said, it’s a matter of how much of a stickler you are about tone. In my opinion, no you can’t really do Marshall tones with the diezel stuff. The midrange doesn’t sit at all like a Marshall, which is where the Marshall tone comes from or Atleast a lot of it. The high end on diezels is also way less aggressive and bitey in general, the mids sit lower and are way more complex and super compressed, it’s just a whole lot different.
On that note, if you turn down the deep and presence knobs to zero on the Herbert, you effectively take out the negative feedback that is inherent in high gain amps that give them “that sound”, and make it behave much more like a fender or Marshall style circuit. It sounds great when doing this, and I’ve coped a very similar eerily close fade to black style tone on my Herbert doing this.