Drew Brees? I'm definitely not saying Trask is him, but brees was short, immobile and didn't have a big arm
Brady didn't have a big arm either coming out. He developed more zip the longer he was in the league(Yes, arm strength is something you can work on). He was a terrible athlete too.
Joe Montana had a relatively weak arm compared to his peers.
Alex Smith has made himself a decent career with a weak arm.
Arguably the most talented qb in nfl history, Peyton Manning, was a terrible athlete and had a mediocre arm.
Chad Pennington, arguably one of the weakest arms for a first round qb ever, also looked great in the NFL before he became made of glass.
Deshaun Watson is lighting it up right now and he had one of the lowest recorded throw velocities of a first round QB in recent memory.
What did all those dudes have in common? Accuracy.
It's the most important trait for a QB. You can survive without a gun, you can't survive in this league without accuracy. Kyle Boller showed us all that.
Not saying Jones/Trask will be good, but they have the accuracy thing down.