Problem using quotes in Profile search?

I'm deleting some inactive users, starting with those who have confirmed unsubscribe from all site notifications and have no other activity on site. I've searched via the 'Profiles' menu tab, for the user name recorded in the Activity Log for the unsubscribe. I'm wondering if putting the user name in quotes is having some unexpected effect...

In some cases, the profile search has returned two profiles. Example: search "Lynda Rance" in quotes, returns two profiles (not on the same account). One is profile "Lynda Rance" and the other is "georgia (Mrs) pogue". I can't see any connection between the two, except that they have consecutive user Id numbers, in this case 15826 (profile Lynda Rance) and 15825.
If I search only on Rance, the profile search only returns the one 'Lynda Rance' profile.

Here is another example https://pmp-art.com/profile/ss=%22sally%20mcintosh%22 which returns profile IDs 68030 (Sally McIntosh) and 68023 (Kidzmom). I can see no connection in the keys of these profiles.
Again, if I search only on Mcintosh, there are several results with that surname, but Kidzmom is not one of them.

Sorry if I'm being dim but can you explain to me what is happening here please?
updated by @lornawebber: 07/16/18 06:31:13AM