NICs are named by their driver type. They can't be renamed. There's no way you reinstalled and ended up with different NICs unless you switched hardware in the process. Just re-assign the NICs either manually in the config, or after you restore the config. That's very easy and trouble-free.
Where you have complex interface scenarios, like VLANs and lagg and bridging, things can be a bit more complicated. Editing the config manually is definitely the easiest route there. If you do edit the config manually, be careful, and never do a blind mass search and replace. Verify every replacement is actually an interface (granted there will only be 1 instance unless you have a more complex interface scenario). There's a good chance you have certificate or other data that happens to contain, say, "em1", and if you replace every instance of "em1" you'll break things.