I understand the reasoning behind bringing in an establishment VP as a counterweight. This will deter the RNC and the rest of the GOP political machine from secretly helping Hillary and sabotaging Trump's campaign as they would likely otherwise do.
However, if Trump needed an establishment type for VP, you're right that picking one from a swing state like OH or PA would have been a better move.
So, Trump was supposed to pick John Kasich, the RINO and closet Democrat? This would have hurt him in the general - not help him. Kasich opposes everything Trump stands for.
Not sure how establishment Pence is, since he’s Tea Party (I’ve heard).