You are only Match-ing on your own gedcompare report for the purposes of your own work, it doesn't suggest merges or anything like that. That's a secondary step where you can compare the two records and manually choose what to add/edit from the existing profile.
Therefore, if there is not enough data for a definitive match, best practice is to private message the profile manager and ask if they have more info. But here's what I do:
1. look at surrounding family for both profiles. If they both just say "John Smith" with no location, spouse, etc. then
1a. see if family has a location/timeframe/relatives that make sense. For these situations, send messages to profile managers.
1b. if your person has immediate family that was born in Canada and the related profile has all their family in New Zealand, they are probably not a match. Reject it.
2. If this is not helpful, and you're not sure it's matching, I found somewhere in G2G that it is easier to Merge later rather than untangle incorrectly merged information. Therefore, I tend to only match on what I can reasonably be certain is a Match, and create new profiles for others.
3. Going through the match/reject process to completion for that Gedcompare *still hasn't added anything*. So, when you get to the point where you *CAN* add, start from a point that you are sure of, and work outwards by trying to source as completely as possible. This will take time, but will probably uncover enough other information that it will help you make decisions when it comes time to add Aunt Jane who may or may not be ten other people.
4. Before you abandon all hope, ask for help here on G2G again, lots of people very willing to help. You can post specific questions about specific ancestors and where you are blocked, and the Sourcerers will jump in to help/offer advice/do their magic.
Hope that helps, good luck!