I think it would be a lot harder than you think. There is a reason a lot of NHL dmen take longer to develop. Guys like Hedman weren't good for a few years out of the draft.
Well Karlsson isn't your typical Dman. The guy has the puck on his stick more than anyone and constantly takes it up the ice on zone exits and entries. He's always among the leaders in shot attempts for.
I think this ump calls strikes/balls on how the pitcher is performing. When Miller was pitching well he was calling borderline strikes. Now that he is battling he is calling them balls. Not the only umpire that does this.
To be fair he is learning pitchers so I'll give him the benefit of the doubt. If another 20 games goes by and its still this bad then I'll worry a bit more. Lucroy is a negative framer as of now as well FWIW.
I think framing will be worth less and less as the years move on though so that contract probably looks bad soon if Martin can't continue to hit.