Since you can daisy-cahin all those fans' RGB connectors together, you need only one mobo plain RGB header to plug the entire group into. Actually, your mobo has two of those, plus two of the other ADDR RGB type of header. The two plain ones are marked LED_CPU (mid-board with 4 pins), and LED_C1 (bottom of board, 5 pins, item 8 on manual p. 13). The LED_CPU header is intended for use IF you have a CPU cooler with plain RGB lighting in it, but if you don't you can use it for other lighting units. I recommend you use the LED-C1 header along the bottom, though, just to keep things clear. It has FIVE pins because it is a variation of the plain RGB system with one added pin for use with slightly different lighting units called RGBW. For your purposes, just make sure the mark on the first fan's RGB 4-pin connector for the 12 VDC pin is aligned with the 12 VDC pin of the header. When you plug in, that connector simply will leave the last (fifth for White) pin unused. This header can supply up to 2 A to the RGB lights, and specs for several Azza Hurricane units say they use 0.4 A per fan for the RGB parts. So you would be OK to daisy-chain up to 5 such fans' RGB units from that one mobo header.
The utility that comes with your Gigabyte mobo to use for control of those lights via that mobo header is called RGB Fusion.