McGrath has these exact same ‘abilities’. He doesn’t bowl fast, has consistent line and length, but is still the leading fast bowler in the world.
And you couldn’t be more wrong about Rana. He’s got very decent pace (can go up to 145-148 kph range), while your average bowler is around 130-135. Rana has got variety too. He’s got a very good slower ball, can swing the ball both ways, and also can reverse-swing. He didn’t get any wicket in Tests in India, but he played only one Test.