<< I had thought you were saying that any one ETL procedure into one database used 14 concurrent threads. But really, each ETL procedure is single-threaded, and there can be up to 5 (or theoretically up to 14) of them running at a time into different databases? >>
Sorry, just caught this. Your first interpretation was correct. Each DB runs an ETL that can have up to 14 concurrent threads. I don't think the number should be that high, but the engineering team insists the load time is better than fewer threads running faster.