>>128194962
1. Grunge isn't a genre defined by musical qualities. Screaming Trees, Nirvana and AiC have almost nothing in common. Nirvana has close to zero Sabbath in their sound. Maybe on Bleach when they were trying to make melvins songs.
2. Billy corgan's favorite band is Black Sabbath. So if you insist on your meme definition of Grunge (doom metal + garage punk) then SP is at least as Grunge as Nirvana and more Grunge than Screaming Trees. I suspect you don't know SP's discog very well. Siamese Dream has Paranoid all over it (fuzz to emulate sabbath's distinctive sound, almost every song has a moment that sounds like War Pigs, Electric Funeral or Planet Caravan) + multiple songs on MCIS are doomish
https://www.youtube.com/watch?v=Htz_U7073i0