Michael, sorry if I'm introducing a pessimistic note to the discussion.
First, the ethnicity results are the least important, and most unreliable, part of your results.
Second, you may quickly find that most of your matches have not provided trees and don't respond to your messages. For me, that problem has grown much worse in the last 2-3 years, as Ancestry went on an advertising binge and sold DNA to many people who had no intention of ever investigating their ancestry in any meaningful way.
But the good news is that those other matches, who tested earlier, are still there. So, by sorting through your matches, you should still be able to find meaningful matches who do have trees, and who might even respond if you message them.
Another piece of good news is that Ancestry has developed some better tools recently, although they still lack what many of us want, a chromosome browser. But the ThruLines can be useful. Just don't accept them without verifying your matches' trees.