It is not technically difficulties to export and import data between tenants.
You just have to chose the best technique depending on the amount of data and your business needs.
But i would not recommend that you export and import the entries tables like general ledger entries, item ledger entries, vendor ledger entries, customer ledger entries and so on.
Then i would recommend that you create journal lines and post the transactions in the other tenant so the entries tables are populated through posting.