Does adding a graphics card for folding diminish the CPU folding numbers? Did I do something wrong?
Yes. No. When GPU folding, pretty much one full CPU core/thread is consumed providing data to the GPU and receiving results back from it.
You basically switched from 3 CPU cores and 1 GPU available for folding to 4 CPU cores available for folding. Based on your feedback, it sounds like a single CPU core does more work than your GPU did.