Hm, the payee is actually just a text list that doesn‘t store any related IDs. In this case, you would use Employer GmbH as payee, and the transaction notes (i.e. Gehalt 01/2023) as notes. Payees need to be curated from time to time (removed, merged, etc).
I moved away from auto importing and simply import manually, due to the many possible payees used by subsidaries (ebay sarl, ebay AG, etc), causing me troubles :D
If you like, you can post an anonymized CSV so I can check out how it would import :)