and he is 5'11 w/o a strong arm
Whoever thought this, hasn't watched him play. Perhaps he doesn't have the arm to show off in pro-day/ combine type settings?
I've seen roughly half of his college games.
He doesn't have quite the arm that Mahomes had, but he's no slouch. (Mahomes is my reference as the last college QB I was personally able to watch who I figured would have NFL success)
On the field, Mellott just made plays, in a very Mahomes-esque style. Nice deep ball. Solid touch passes. Outlandish throws.
Of course it's his ability to run and evade that make him such a threat. I agree, given his size, he probably shouldn't be considered for NFL QB, based on his arm talent alone. However, as a whole package, I think he is worth a late round flyer.