sorry for the late reply
On Petry, @dlbalr has pointed out multiple times, on my trade proposals where i include him, how low I value him. He is right, so please take my skewed view into consideration.
I think that an established team that is missing offense from the back end, Petry fits well if not for cap hit.
He is not a good addition to a young team with weak leadership; think of him as the equivalent of Drouin with respect to leadership: a complementary piece you do not build on.
Petry has always performed poorly defending one on one or on physical games. He has excelled on the PP and when paired with an Edmundson: I praised Edmundson's signing because he makes Petry so much better.
All these considerations, makes it difficult to find the right trading partner. What would I expect to get in return for Petry: a late first and a D prospect with the potential of Norlinder or Harris. Or, in advanced stats, a replacement for:
Expected Goals differential of +6 to +12
Point Shares of +7
Points/Season: 40 to 50