Dude,
I know you are fairly new to metal, but this might be the most ridiculous thing ever posted on this forum.
First off, I won't even bother to comment on Pantera. Their 90s output was MTV tough guy metal for jocks. If anyone likes them, well then good for them. Their sound altered certainly though from CFH through their last one.
Secondly, Sepultura. You realize their 90s albums were Arise through Against? That includes the highly commercial Chaos AD, as well as the very modern / nu metal Roots. I don't think any fan, nor any member of the band itself, would agree that they were consistent in the 90s.
Finally, you 100% fail to even consider what was going on in the underground during the 90s. Right off the bat, let's take better known underground metal bands, in Blind Guardian and Iced Earth.
I will gladly pit BG and IE's output in the 90's to your PANTERA and SEPULTURA in a battle of who was more consistent.
Sorry bro. I am usually pretty easy on you, chalking it up to inexperience, when you say something out of left field, but this one I can't ignore.
Please take it as constructive criticism, and nothing personal.