John; I wasn't with you, so take this with a grain of salt. I might be totally off base here
When I got my HDS, I was comfortable looking at my old Lowrance fishfinder. Therefore, I ran it similar to what your photo shows (FF, GPS, Sidescan). However, I found the FF to show all kinds of marks that really weren't fish (but looked like fish and bait). When I ran my FF and Downscan (side by side) I noticed the downscan showed more realisticly what was under me. Often, what I thought I saw on the FF was just junk (clutter). So much so, that I rarely use the FF anymore. The downscan also showed fish and bait when I was running at speed (the FF did not).
Run them Side by Side and see how they relate. I was amazed
5th (Marty)