Johnson had a great first year or so, helped by his unusual slingy left arm action which was difficult to face for the first time, this gave his stats a kickstart but since he has declined and now only performs with the ball 1 in 5 matches at best. Batting is a sideshow for me, scoring 50 is no good if he's bowled 20 overs with figures of 0-110 and the opposition have racked up 500.
Anderson on the other hand had a woeful start to to Test career and ever since has been battling to bring his average down. He has led England's attack all over the world, consistently gets the best players in the opposition out and rarely breaks down with injury. Anderson DOESN'T perform with the ball 1 in 5 at worst.
I would say that if you looked at their careers they have very different growth curves and I expect the stats to back this up
'He bowls to the left, he bowls to the right' wasn't penned about Jimmy Anderson