I'm still learning all this, and have a related question I think I can ask intelligently.
In order for ancestry to consider you and someone a match, they must be looking at those segments as well. It seems to me that in addition to just showing individual matches to you, they could show groups that you are part of that also share the same segments. In other words, these 5 people matched you and each other on this specific thing or things. That seems a lot more useful than going through each one, and keeps it within their site instead of having to download and use other tools. Is the problem those groups would be too large to be meaningful, or is it just not a useful thing to have (or more likely, they just haven't done it)?