split cables

I've a Corsair RM850e and it comes with 1x 6+2 pcie cable and 1x split 6+2 pcie cable, 850e included cables; I know people recommend separate pcie power draw to a 2x8-pin gpu for safety like in here; but that doesn't say anything about if we can safely use the split on other single 6+2...

I'm trying to add 2 fans in 1 header using a splitter, the Cool master fan is 16 amp but the Antec says nothing but it's brand name and logos around it. Is it safe to go with it or should I replace it? Both of the fan were reused from my old cases from when I was in elementary, now I'm in college