If they're supposed to be binary-identical data (same file checksums), you can use BiglyBTs Swarm Merging feature - without manually copying (which isn't as reliable due to the start/end of the files not bordering on the chunk boundaries.
If they've been modified in any way though, this won't work. However, you might be able to use its Swarm Discovery to find other torrents with the same data and complete with Swarm Merging.
If anyone's unfamiliar with this client, it's been around a long time, and was previously named Vuze (and before that: Azureus)!
Tis been under active development by the two main devs for all these years. The adware crap was removed from day 1 of the fork and it's a really solid (and featurefull) client. Highly recommend. Also does I2P.
The absolute best feature is Swarm Discovery and Swarm Merge, which lets you find identical large files across different torrents and cross-seed and merge said torrents while downloading both. With Swarm, I've been able to download torrents with <1.0 availability - completing both torrents and become the seed hero. And this was before it supported the v2 BitTorrent spec (which gives you individual file hashes).
I still use qBit for my *arr automation but BiglyBT is always there for everything else and as a great backup client.