Actually, George Martin has always stated that George Harrison was the most accomplished and technically correct musician of the Group. He was four years younger than John and Paul, and worked hard to gain acceptance into "The Quarrymen", the band that John and Paul began playing together in when they were both 14.
As for Richard Starky, aka Ringo Starr, he was actually the only professional musician of the group when they hired him to take the place of Pete Best. Starky played with "Rory Storm and the Hurricanes", probably the most popular band from the Mersey Beat Scene before the Beatles exploded into an overnight sensation, after six years of attempting to succeed.
The true artistry of the Group, as has been pointed out, is clearly the Songwriting team of Lennon and McCartney. A prolific pair of writers that scored more songs and hits than Rodgers and Hammerstein. Their bond went far beyond the musical world, both sharing a loss of a Mother in their teen years (Paul's Mother to Illness - referred to as Mother Mary in "Let it Be", and John's Mother was hit and killed by a bus - referred to as Julia in the song "Julia" off of the White Album).
The pair began playing together when they were 14, when John was impressed that Paul could tune a guitar, and Paul was impressed that John knew all the words to "Twenty Flight Rock".
Regards,
------------------
Midnight
Midnight Ventures Partner Program
Excellence is not an act, but a habit - Aristotle