Azure Data Factory

In our ‘rebuild’ project we are transforming all our old services into new subscriptions, all created and managed by Terraform.
But, we have over 200 DataFactories, creating them with TF is not a problem, but we invested quite a lot in writing our own generator. We connect to the original datasources or we describe them, then USql statements to verify data, SQL stored procedures to create staging/production tables and stored procedure to merge (yes/no with incremental uploading) are created. Also the complete data factory ARM template is created.
It would be quite a investment to transfer this to TF, the creation of the DF is not in the ARM script, just all pipelines,ds, …
Is there a way to automatically join both in TF ?

I saw azurerm_template_deployment, but is this a good approach ?