I have also tested this many times and I hardly see much of a difference. 10% sounds like a lot. What is the quality of your router and wifi, is it some cheap chinese junk? From what I can see there is less than 1% difference between wired and wifi.
MikroTik RB2011. I dont think that it looks like "cheap chinese junk". I was not looking where is problem. I had seen the difference and solved this problem with wired connection.
MikroTik is a security nightmare...backdoors and vulnerabilities.
Go wired with more than 2 rigs period, otherwise you start losing rewards significantly. Even with 1 rig it will slow you down a bit but impact started showing up after 2 rigs when I tested it.