Hi,
if there are not to many rows in the Excel file I would do the following in a "Processing" workflow.
Since I'm not sure how many workflows would be created/updated I would do this in batches
Step 1: Import the rows two an item list
Paths "imported", verifies whether there is already a workflow or there is an existing one. This will update the item list with the workflow id and an action what should be executed (create/update)
Step 2 Processing
Timeout 1 minute which moves to a Workflow control step
Workflow control step
-> Checks whether a number in technical field is greater than the last processed item list row id
If not
a) Process xx rows from the item list, to start/update workflows
b)update the value in the technical field
Back to step 2
If no more rows remain move to step 3
Step 3 completed
Best regards,
Daniel