I would say it was according to what motherboard you are looking at for this build, and what your future upgrade and usage path look like.
That R5 1600 is no slouch. If you don't plan on overclocking, good with A320 or B350 board for OC. No BIOS Issues. First gen CPU and chipset tend to be finicky about RAM. Pick something off the QVL if possible.
The R5 2600 is a bit faster. Would be perfect for a B450 motherboard. If you go with the 2xxx CPU with any of the 3xx motherboards you could have issue with boot related to BIOS. Much more RAM flexible on 2xxx and 4xx.