I didn't argue that the guys I mentioned fit the parameters set by the OP, I only cited them as evidence that the artists you offered (I don't include Ray Charles from your subsequent post) weren't quite as unique as maybe you implied.
That said, I'm still not going to argue the Beatles and Stones. As I stipulated, you can hear the Blues (The Stones) and R&B (Beatles) influences in their earlier music, but their sound was their own; And in the case of the Beatles, they evolved significantly over time.
As for Elvis, Maybe we're just interpreting the OP differently. Elvis' music wasn't original. Not at all. As you said yourself, Ray was doing it, as was Roy Hamilton. Seriously, listen to a early Roy Hamilton ballad with his phrasing and vibrato and tell me it doesn't sound like Elvis before Elvis.
Elvis' songs weren't "songs that sound like nothing else". They were simply songs that sounded exactly like songs that White America hadn't heard yet, coupled with a stage presence that white girls weren't previously allowed to see as sexual. That's not nothing. I can't imagine the guts it took, and no one can credibly argue against Elvis' cultural impact- I'd go so far as to say that it hasn't been matched before or since. But I didn't see this as a thread about the cultural impact of rock artists. If it were, The Beatles, Stones, and Elvis would all be in my top 5.
Fun topic.