Dude, you're just flat out wrong. You need to give it up. The chronicles have proof that Death magic is COMPLETELY SEPARATE from Arcane
"Main article: Necromancy
While the Kirin Tor consider necromancy to be a school of arcane and it has been described as an arcane art,[80][81][82] World of Warcraft: Chronicle Volume 1 explains that necromancy is a separate branch of magic part of Death magic."
And you're also INCORRECT that you can't "create something from nothing" when there is literally ANOTHER quote saying that is exactly what happened
"Order is most commonly perceived in reality as arcane magic. Arcane energy is innately volatile, and wielding it requires intense precision and concentration. Disorder, on the other hand, manifests as highly destructive fel magic, a destructive and extremely addictive energy originating as a result of the mutual destruction of Light and Void as they collide on a cosmic scale in the Twisting Nether."
Like you're just wrong.
There are six types of magic in the universe. Arcane is merely ONE type of magical energy. It's opposite is Fel. Light's opposite is Void. Life's opposite is Death.
They are ALL separate.
In the beginning of the universe were pure Light beings and pure SHADOW beings (not arcane). They fought and created the universe including Arcane, Fel, Death, and Life magics.