Gul and Mortaza started making their mark around the same time-both same age. At the beginning Mashrafe was slightly better-more pace, more aggression, more heart. But Mashrafe's multiple injuries slowed him down. Gul kept developing and today is a much better bowler. Even these days Gul can bowl in excess of 140 kph. But if you compare their records, they are pretty much neck n neck in ODI's, Mashrafe played a few more matches. Gul has done far better in tests.
Rubel was quite quick when he started 140+. Dont know what happened