I don't see evidence that Perkins has arm enough to make a D respect him. Maybe I'm wrong - saw only highlights of his preseason and college and know what I read. I don't see him giving NFL D's more than occasional fits. One game's worth of tape and opposing D cordinators will have him figured out.
Jamarcus Russell had an all-time NFL arm. Problem was, he was all arm and no personal aptitude. It takes enough of both to play QB in the NFL. Running ability is a luxury.
At some point in the NFL if you're going to play quarterback you have to make most of the throws, if not all of them, from the pocket. You have to get rid of it quickly and have some zip on the ball. Not wall-shattering zip, but enough to beat a corner closing on an out pattern. Warner certainly had that, and he could throw deep. Az Hakim, Holt and Bruce would testify to that. "Weak" is a relative, not absolute, term. Where does Perkins fall on the scale? Comparisons to Warner or Montana (WEAK arms? Really?) make no sense even in regard to arm strength.
Is Perkins a decent backup? For now, not enough evidence and under these conditions who could tell? Same might be said of Wolford. He did as well as could be expected with half his dropbacks ending in disaster from a leaky O line and all but a few rare great ones would get gun-shy under that kind of pressure. Warner was extrordinary in his ability to get up, again and again, and keep throwing. Brady, not so much.
Perkins to his credit didn't wilt. The coaches knew of that and his running ability coming in. If they thought he had as much arm as Wolford, even, he'd have been the #2 QB much sooner.
Much as we'd all want him to be, I don't think he's the next Lamar Jackson or even close. I hope I'm wrong, but think I'm right.