Great list, though you left out some stuff.
I’d include early alternative metal. These are the bands from the late 80s and early 90s that blended metal with various other genres like funk, post-hardcore and grunge. This would include bands like Faith No More, Jane’s Addiction, Helmet, Rollins Band, Alice In Chains, Soundgarden, and countless others. These are the kind of bands that influenced many nu metal bands.
Metalcore should also be included here. I don’t listen to it so I can’t really give recommendations, but I know it was one of nu metal’s spiritual successors in the mid 2000s. I also know that many metalcore bands are inspired by nu metal bands, so much so that nu metalcore is a thing.
One of my personal favorites is Gojira. They could have been included under groove metal, though they are very experimental and deserve their own entry. Gojira blend groove metal, prog metal, post-metal, and technical death metal in their music.
If you ask me Aenima has a lot of nu metal elements. Lamb of God's As the palaces burn is an almost fully nu/groove metal album. Also yes, nu and butt rock go hand in hand, were the first styles that introduced me to guitar music
Respectfully disagreed on the TOOL & lamb of god part, but irregardless, I am happy to hear Nü-Metal & Butt Rock got you into Guitar Music
Black Veil Brides.... Really? No..
This has a fuckton of Butt Rock energy lol
Serious question: is RCHP butt rock?