I agree Brockers has been nearly invisible this year. He is a very talented guy and Donald is getting lots of attention so you would expect Brockers to standout and make plays. I have similar sentiments about Suh. In fact I thought the DLine would dominate but other than Donald they have really disappointed me with their lack of performance.
I will say that with Fowler our pass rush as a whole has been pretty good but we still need to do much better against the run and Brockers and Suh should be making a lot more tackles.