To begin, I would not exclude any of the pages from Google or Bing if they are to remain in some form or other. The reason is simple. You never really don't know how search is going to behave from day to day and I would rather give options for search than take them away. It may be that John Smith Places He Grew Up In will be of more interest than the Overview. I have been surprised that odd little do nothing pages end up being ridiculously popular compared to a page I worked weeks on researching and getting exactly right. You never know. It is all about the person searching. We can only guess.
I would just create a tightly tuned Overview page if that is what you want. And for the record, it sounds like a good idea for the user to me. I would focus it for general John Smith search covering the search terms you have seen used for the other pages and any others that I can discover that makes sense. But do not chose too many keywords and do not over perform taking traffic away from the other pages. If your SEO work is done well, each page should perform as it should, but for less specific John Smith searches, the Overview page may be offered first. Especially if you use keywords like overview, profile, etc. Be sure to breadcrumb all of the John Smith pages as a topic cluster and to do this for Jake Elwood too. (humor)
Use theme pyramids and the headline read order.
Used to organize content from a user perspective and possible in a directory/page structure. Determine the most important keywords for each page and directory for the structure.
Used to focus keyword use. Use the most important keywords for the target page in each of these elements where you can.
Of course, this looks like a no-brainer, but you would be surprised how often this is ignored. Your title
description meta-tag should be related. I usually write the title and expand it in the description and then reiterate the title keywords in the
h1 tag and then in any links.
If you 301 to the overview page, you may lose all of the advantage you have today. One of the metrics is the age of a page. If your page is 5 years old (for example), that is a metric that helps you in certain searches especially for topics like history, profiles, etc. Some of the metrics would be transferred but not all as long as the 301 remains and links point to that page and it remains indexed.
I think in the end, you would be disassembling advantages that would take more time to get back than you would appreciate. Remember, you can tune each page and the more pages you have on a topic, the more opportunities you have to tune each page for search. But then again, it may be the topic structure no longer makes sense and why you want to make the change. In that case, then perhaps a change is in order. Whenever you change things up on a search engine, it takes quite a while to get your juice back. I have always been a firm believer in providing opportunities to search engines. You do not want 100 pages for John Smith, but you do want pages that perform well and topics that searchers want.