Grunge has none of the rhythmic sophistication of Cog.
Sophistication? What? Clean tone noodling and a few stop-start riffs followed by strumming? The only part of the track that passably competent is the drumming.
I think it's obvious that the band is foundationally a grunge band, as is Tool. The vocals, contrast between clean/distorted sections, guitar riffs, and themes are within the constraints of that genre. Dressing it up a bit does not change that.
My sincere guess is that you're unable to perceive the differences between grunge and a band like cog, the same way people who have little exposure to modern art might lump surrealism and dadaism together.
Do you know what a polyrhythm is?
Do you know what 7/8 time means? And 9/8? Both of which are used in the Cog song.
There is no progression between different time signatures in grunge! Differently, there is no use of non standard time signatures in grunge!
You'll probably say this is mere 'dressing up'. But who are you to say that the manipulation of rhythm and pulse, an order of magnitude beyond the norm, is mere 'dressing up'. This might be like me saying, the use of chromatic 'riff salad' compositional techniques in death metal is just the 'dressing up' of NWOBHM and speed metal. Pfff.
Alterations between clean and distorted riffs? But we have this in 0peth! 0peth aren't bloody grunge now are they?!
And what objective features of that retarded Ildjarn track makes it profound? I'm starting to worry about you. Don't get me wrong, I love good black metal, but defending that track just because it's a certain band rings immediate alarm bells with me. I even like some Ildjarn.