I'm pretty sure that the NM FATEs for the daily Hunts are specifically chosen as ones that both spawn around the same time, making it very difficult to complete both quickly. This wouldn't be a problem if certain NMs didn't spawn so infrequently - it's frustrating to see a FATE end just as you arrive and then waste over an hour at the least standing there waiting for it to next spawn (Seps is probably the worst for this, but others are equally frustrating for their infrequency).

But like Bixillarla said, I don't see SE changing this now so long after it's introduction sadly.