I also use two switches after my router. Router to switch 1 is Ethernet. Switch 1 to switch 2 is fiber, switch 2 to my server is a short Ethernet.
Why two switches? To break the path of any galvanic noise riding on the Ethernet cable. Then work hard to minimize the chance of picking up any other galvanic noise to the server.
Having said that, with my MSB Premier Digital Director after my server cleaning things up prior to the DAC, I can honestly say I cannot hear any benefit of the two servers - anymore.
I keep them because I have them. They do no harm.