Correct RAM installation?

[Hidoi]

I have 2 ram dimms at 2400 mhz, single rank and looking at this from my motherboard's (asrock x370 killer sli) manual:

It seemed to me that I could install my ram anywhere. I do know that when using dual channel you're supposed to skip one slot, so I've installed them on A1/B1. The system works fine, no complains, but then I came across this from MB FAQ: 

And now I'm wondering if I should switch to A2/B2 ?

[pstarlord]

To my knowledge that's the standard.  If you have 4 slots, you populate the second from the left and the far right slots first. (A2 and B2)