If you read some of @IllmaticDelta posts, it shows that what Kool Herc was doing was separate from what Jamaican crews in NY were doing at the time. This is according to Kool Herc.
My understanding has always been that Grand Wizard Theodore invented the scratch in NY.
It was a an exclusive NY phenomenon though. Unless you've got proof that other cities had similar scenes doing the exact same thing? Which I assume you don't, since your post says this is the only proof you got.
I read and watched them all...
If you read my post...
You would see that the Jamaican djs lacked instrumentals, but rapped full songs. Which would require live looping.
But again. You can have scratching. A New York nikka invented scratching. New York brought scratching to black culture. That doesn't include playing beat breaks. But scratching as a beat?
The concept of a selector and an mc is a island phenomenon... And then a Jamaican Dj came to New York and played beat breaks. And an emcee rapped over it.
So even tho you have no proof that herc didn't scratch first. Or that the idea came from an original thought of a New Yorker not from the islands, we can say that scratching and sounds from the turntable came from New York. The music can/does/did definitely exist without that. Lol. The rap part especially.
You cant act like the use of a turntable started in NYC but maybe making parts of the song out of scratching the record against the needle came from NYC. That does not mean they invented any of the culture we have today.
((I don't see how you can say for sure people in Miami and Jamaica didn't scratch records? But it really doesn't matter. ))