I got the same RFE letter asking for independent letters for my NIW last month from VSC.I am still working on it now.
From the exact identical sentences in both of our RFE letters, it seems they came from the same officer. what is the number of your officer (it's shown on the bottom part of your blue color RFE letter)? How many citiations you have? Maybe we can share some information and help each other a little bit.