I don't think Heinola's ceiling is Pionk, because he has been protected his whole career from matchups against top 6 players, where Pionk has been thrown into that fire since day 1 as a Jet, and I think that has to do with physicality.
The puck movement aspect perhaps. That's where the Jets can use him, and I think Miller is the kind of a d-man that could insulate him.
It will be interesting to see how the Jets move with him. Certainly skating defenses this year have had some success in the West, Calgary is a good example, Colorado is starting to heat up again. I think that 2nd PP would have some more options with Heinola as the primary puck carrier, playing opposite Perfetti in the diamond. Heinola's ability to cut seams with passes probably fits well into the way the Ehlers line plays, and seeing a skater in that group that could read off them, and move the puck while attacking, could open some more opportunities up for that line that Stanley and Fleury haven't been capable of.