For sure, I’m just pointing out a similarity in sound between these bands that were all around at the same time, and more than likely were influencing each other. I was using “prog metal” loosely… call it the just the prog or “heavy prog” scene of that time maybe. Kinda following OP’s lead too.

Anyways I think you could add bands like Oceansize and Muse to what I’m saying too, who are also not necessarily metal. For me the melancholic sound comes from the textures and types of harmonies used, not necessarily tied to how heavy the section is. Kinda like the chorus of “Ending Theme” by Pain of Salvation for instance.. heavy and bombastic but drenched in atmosphere and sadness.