Rudolph has good arm strength, Not a cannon but not weak either. You know who has a weaker arm? The great Lamar Jackson..
The combine puts the radar gun on all the QBs. Here's some numbers for comparison
Josh Allen Wyoming 62 (Left) 62 (Right) - That's a cannon on the high end
Cam Newton, Auburn 56
Patrick Mahomes Texas Tech 55 (Left) 55 (Right)
Russell Wilson, Wisconsin 55
Justin Herbert Oregon 55 (Left) 54 (Right)
Dak Prescott, Mississippi State 54
Mason Rudolph Oklahoma State 52 (Left) 52 (Right)
Joshua Dobbs Tennessee 51 (Left) 50 (Right)
Lamar Jackson Louisville 49 (Left) 49 (Right)
Deshaun Watson Clemson 45 (Left) 45 (Right)
Rudolph's arm strength is fine. The reason some of his throws flutter is because he lacks confidence. You can tell that he's trying to guide the ball in there instead of just letting it rip. He was put in a horrible situation last year. The OL was struggling. Conner was hurt. JuJu and DJ were hurt and Washington was underperforming. There were no weapons. Despite that he did look good in his first few starts but after he got knocked out, he came back and played scared. Scared of the boos and letting down the team. Duck looked better because he was just chucking it without thinking.
Now Rudolph is thrust into a game the steelers are losing while already in FG range and is no doubt under instructions to just not mess up the FG attempt. He looked hesitant but still he did fine. I don;t know what people expected him to do in just a few plays cold off the bench.
Rudolph is a fit for the offense the steelers want to run. It is apparent that the steelers want an offense based on short, run after catch type routes and some deep shots. That is what Rudolph did at Oklahoma State.