You've had your Google Ad Campaign(s) running for a while now and they're generating a decent cost per conversion. Maybe it's even a profitable cost per conversion.
You can't help but wonder if you'd see better results however if you were to restructure your campaigns and ad groups. You've read up a lot on how to structure campaigns and ad groups since you originally started with Google Ads and you definitely think it can be improved by a little restructuring.
You're just worried it'll make your results tank and you'll have no way to reverse course to minimize damage. Should you even risk it?
In my opinion, so long as the current campaign is generating a profitable cost per conversion, I'd avoid making any major restructuring. There are a lot of optimizations you can make to a campaign to lower cost per conversion that don't involve a major restructuring.
If your campaign isn't converting well, then I suppose it wouldn't really hurt to do a restructuring of campaigns and ad groups. With that said, I still think there are a lot more optimizations you could try to the original campaign to increase results.
Minor restructuring of ad groups shouldn't be too big of a deal but it still might be worth running a Google Ad Experiment so you can easily revert course if the changes don't increase performance.