Cliff Richard got his start in the Shadows, so it's not surprising.
Don't underestimate The Shadows - they may sound tame by today's standards (and look like complete and utter nerds) but they were probably the most influential European band of the 20th century. They set the stage that allowed the guitar-centric music of the '60s to happen, they made the guitar an instrument in it's own right, instead of just being one of the instruments that supported the singers. They were direct influences on most everyone who followed, from the Beatles to Black Sabbath and Motorhead.
In fact I believe that he turned a lot of rebellious young guitarists in the early sixties away from the Strat, which only got undone by Hendrix.
Not at all. Paul McCartney, Jimmy Page, Jeff Beck, Peter Green, Eric Clapton, Pete Townsend, Brian May all first picked up a guitar because Hank Marvin. What caused the trend away from the Strat - or rather the trend towards the Gibsons - was the humbucker equipped Gibbys could make an amplifier distort more than a Strat could. Hendrix used a fuzzbox for more distortion, which got around that, and the Strat became more viable as a rock instrument.
Ever notice how British guitarists tend to go for red guitars (Mark Knopfler, Gary Moore, et.al.)? That's purely because Hank Marvin played a Fiesta Red Strat.