Should be do-able. I broke it down into 2 workflows for efficiency reasons. The first one has a list of months and figures out which month is which numbers. Then for each month, it starts a secondary workflow.

Note that the months are in order in the "Months" token, so the iteration number in For each value corresponds to the month as a number ("1" for "January", "2" for "February", etc). The month as both its name and the number get passed into the second workflow as input parameters.

This second workflow searches for all documents with names containing the given month name. You will most likely have to tweak the search criteria there to narrow down your results as needed.

Then for each search result, it runs pattern matching to get the other date parts and then combines them back to rename the document. Since we already know the month number because it was sent in from the first workflow, we can just use the input parameter's token in the document name. I formatted it as D2 so it would get a leading zero for months 1-9.