I donāt think there is any magic sauce to it. He on his own figured out his picking system unawares and mostly worked on his left hand consciously. Hereās the thing that sets him apart; he really did OCD with a guitar for at least 5 years. Weāre talking about every waking hour for that period, Yngwie always had a band, but they never played out, when they did it was much later. I forget the exact dates etc, but Iāve read both, his autobiography and the biography, also Iāve heard accounts of him on forums etc from people who knew him, even in the Steeler days, he practiced constantly. The kind of dedication is not for everybody, heād go to sleep playing, wake up and start playing with his left hand on the neck before opening his eyes even, heās continue this one hand playing while he made coffee and breakfast with his picking hand. Heād play while walking to the bus, waiting for the bus, on the busā¦ you get the idea.
I think anybody can do it; but not everybody has the time and absolute bloody minded dedication. Growing up he did little else those last few years, till he started a band in that studio basement of his grandmothers, he had little social contact before that. I think he gained respect from musicians before he really had any friends!
Build all that up to exploding in America, he was primed and kept practicing regardless. I really do think with all this knowledge we have about picking, anybody can do it with extreme handwork IF one has the aptitude.