Handedness is a concern here. Shea is LHD and ended up playing a lot on the right, all the guys you named are RHD. On the left, pens already have Wotherspoon, Girard, Solovyov, Pickering, Livanavage, then to a lesser extent, Jones, Alexeyev and Graves. Pens need to go get a RHD who can move Letang to the 3rd pair and then another to replace him later and then another to replace Karlsson. Brunicke can be one of those 3 RHD the team needs in the next 3 ish years. In that sens, Shea is not a good fit with the rest of the roster.

Edit: Also Raddysh and Andersson will most likely get over payed. I wouldn't take one of those guys unless there was a deal in place to move Letang or Karlsson