In my mind, I imagine Delton throwing a bad ball, but he must be even worse in real life because he's a far better runner than the other qbs.
Delton is definitely a more explosive runner. As for his arm, its hard to say because we haven't seen him through. I can only attest for seeing him several times in high school and IMO his arm was okay, but not great. In any case, it appears that he has at least moved even, if not ahead, of Hubes. This is a good thing.
I think Ertz has potential to be a solid QB the next couple of years. I think Dimel/Miller think they have another version of Klein with him.