new ram in Inspiron 570

I have an old Inspiron 570 that I have been using to run a little consumer grade weather station. The weather station finally gave up the ghost and the new one that I got doesn't need to be hooked to a PC. So, I have decided to turn my 570 into a "shop" PC that I can use to play music and look up repair videos or parts on websites. The PC is working well, I installed an Athlon II x4 640 years ago and I just installed a SATA SSD. I have 12gb ( 8gb stick and a 4gb stick) of RAM in it at the moment from my Inspiron 3650 and it is running fine (upgraded the 3650 to 16gb). I have the RAM in the 2 closest dimms to the CPU. According to the manual those are Dimm 1 and Dimm 2, and the manual says that if 2 sticks are to be installed, that dimm 3 and dimm 4 should be used. In one of the threads about the 570, a Dell moderator said that the Dimms closest to the CPU were 3 and 4???? Was there a typo in the service manual? The reason I ask is because I am gonna be removing the installed RAM and putting in two 8gb sticks (already tried it and they work) and I would like them in the proper slots. Having said that, If the computer boots and CPU-Z says that it is running dual channel, unganged, does it really matter if I am not using the recommended slots for 2 sticks of memory?