[dfawcus]

"Because it's basically a dialect OF English."

I'd suggest not, it is a peer / sibling of Modern English, and descended in parallel. Northumbrian Old English eventually became Scots, due to the 'English of the Lothians' using it (and eventually 'Inglis').

Go read some older Scots from around 1600, you'll probably have a harder time of it than the same age English because they were and are distinct. Modern media, a lack of formalised spelling, and simple economics post union has probably been the major factor in its slow decline towards death.

So Scots (in its various dialects) and Geordie/Mackem/Northumbrian are I'd suggest dialects of the same language, not being English. Speakers code switch between them.

You've also missed out the other language, which was spoken in the 'Old North' and the Kingdom of Strathclyde - i.e. the Brythonic speakers.