I think the two players care much less about who is better than the fans here. Mustafiz said Amir is his idol and wished him happy birthday few days ago. So looks like they get along well and as professional athletes they do compete but its a healthy one.
But the reaction and sarcasm from some Pakistani fans (ie. Syed1) -- Amir mops the floor with oh whatever his name mufasa or Mustafa, oh he is the second coming of McGrath and Walsh etc...is just really condescending. Fizz is no Walsh/Ambrose/Wasim/McGrath or even in Steyn/Anderson level yet but he is a more than decent, very effective bowler.
I am not Pakistani but won't be condescending to Amir. He is a fantastic bowler. Terrific to watch.
And the Bangladeshis know it better than many. Coz the BPL franchise picked him first, it was his international exposure after the ban, and he paid the trust more than 100%, which eventually led to his return to intl cricket.
I just don't get why the fans have to be so bitter and arrogant.
Good luck to both Fizz and Amir. I hope they will dominate the fast bowling in the coming years.