Not discounting what you're saying, but you should probably do a couple of other things before trying to get help from Ancestry on this. (Only because you're very likely to get a runaround from Ancestry customer service unless you're very prepared to refute their explanations.)
Unfortunately, those other things all involve segment comparison, which Ancestry doesn't offer. In about seven weeks, GEDmatch.com will be accepting uploads again. You can use it to see if you and your wife are DNA-related (I know you don't have a known paper trail) and also if she has any matches there from Ancestry that you expect to be yours, not hers. If she does, then you can see the actual DNA connection. Likewise, if any of her matches here are using GEDmatch and *don't* show up as matches there, you have real evidence of a screw-up.
Meanwhile, just because your wife is a DNA match to someone who has *your* gg-uncle or hometown somewhere in their tree, that still doesn't mean that it's not her match.
After I had one parent test here, I discovered that many of my "obvious" connections with leaf hints weren't possible because they were actually DNA connections to the other side of the family. My Dad could have easily said, "Hey, my wife is getting all of these matches to MY family!"
However, in a couple of those cases, I've gone on to find the match's actual DNA connection to my Mom. It just happens that sometimes some people have a strong paper trail link to one parent but a DNA connection to the other parent.
You didn't say whether you and your wife have similar backgrounds. If her parents are both immigrants from China and yours are both immigrants from Sweden, then I'd be concerned. Otherwise...
Over on another company's boards, one researcher has found that her husband is an unexpected DNA match to her first cousin. I believe she's gone on to work out the previously unknown connection. It really is a small world after all. :)
I'm not saying this is what's happening in your case. You may have an actual issue. But, from what you're describing, it sounds like your concern is that some of your wife's DNA matches have a close paper trail or geographical connection to you. That's not proof of a problem. There may *be* a problem, but that's not proof of one.
Don't forget that each match between two people involves considering over 2000 ancestors. (Over 1000 ancestors per person within autosomal range aka 10 generations.) Just because your wife matches someone with a link to your gg-uncle doesn't mean that's where her DNA connection to the match lies. It really could just be coincidence.
Like I said, my maternal grandmother and father here share over 100 matches of varying degrees of confidence. Over at another company, my parents both have the same person as one of their top matches, matching on completely different segments. I've sent I don't know how many messages to people here to say "Hey, that leaf hint from Ancestry can't be to our DNA connection because you are shown as a DNA match to my Dad instead of my Mom."
So, again, Ancestry customer service is probably going to be an unsatisfying experience unless you can give them some hard evidence (segment information) that your wife is not a genetic match to her matches. But, no harm in asking them! After all, they do make mistakes sometimes. I've only mentioned all of the above because your situation doesn't necessarily sound unusual, and I don't want you to be frustrated if Ancestry customer service doesn't scurry to "fix" it. :)