This is an interesting challenge. It may be doable, mainly depending on if it is possible to get to the data_out of the last LED in each fan. There was a thread on this forum wherein a guy used a Corsair LED hub to do the data line daisy-chaining of some other brand of fans - I think Thermaltake. That is all a Corsair LED hub does. If there are actually 4 conductors in the RGB tail from the fan, and one of those conductors is data-out of the last LED., if you can get the RGB connectors that Corsair uses and put them on the RGB tails from the fans, with the right pinout, then the Corsair LED hub will do the daisy-chaining internally. He did have to cut a trace and solder a jumper in the Corsair hub to make this work. Here is a
LINK to his post. If the last LED data_out is not brought out into the cable then I don't think it's possible. I guess you could make a new 4-condiuctor cable that replaces the one that comes with the fan, whose 4th conductor is attached to data-out of the last LED. Then you still need to do the daisy-chaining, so Corsair LED hub.
I saw another post wherein a guy installed small strips of spring loaded terminals inside his PC case. He gathered up all of this various devices with RGB, cut the factory ends off, then split the individual conductors out and landed them on these little terminals. Then did the same on the other side with all of the Farbwerk360 RGBPx ports. Then he made little "patch cables" that allowed him to cross the conductors in whatever pattern was required. It was a very elegant solution and beautifully done. Seemed like a lot of effort for blinky lights. Some people just like to do stuff like this. So it's possible, but may require some expertise with crimping contact pins onto small wires, some soldering, and a lot of patience. Good luck!