Well, it actually is a different approach. Just because he came from the Sox does not mean he is the same type of coach, as I explained earlier.
In fact, you seem to be advocating for the same old approach by getting a coach well-versed in mechanics (which Bush may or may not be). But those candidates largely fall into two categories:
1. Experienced pitching coaches who were fired by their previous organization
2. Inexperienced candidates who have never been an MLB pitching coach.
Which is preferable? And how is either better or worse the Bush?
Bush might fail miserably, or he might succeed. But to say he is the same old as LaVangie because he came from the same organization is just silly. That's like saying the Sox should unload Bobby Dalbec because Lars Anderson was a flop...