Hi,
I don't find any good reason why there are two files. There should be just one, where you specify everything you'd like to done.
If the tech team doesn't want to correct and leave just one file, may be because they are lazy or there might be some other issue that if they delete one file, the hole site blows up.
Here, I leave you 2 Moz's articles about the robots.txt file.
What is Robots.txt? - Moz Learn
Learn About Robots.txt with Interactive Examples - Moz Blog
Take into account that the name of the file must be in lower case. I've never seen any different and the servers are usually case sensitive with the filenames.
Hope its helpful.
GR
