At a glance, given that the bonuses's for Daily/Weekly hunts are so pitiful, it's hard to imagine that the developers foresaw so many people grinding out hunts so quickly. They SHOULD have seen it, given the rewards, but alas...
..Anyhow, I don't really mind the developers adding in alternative means to acquire Sands and Oils, in fact it struck me as largely inevitable that they would when 2.2 hit. However, it also seems to me that they've inadvertently opened the flood gates just a little TOO wide.
Again, a weekly cap on allied seals would probably be the smart move here. Additionally, i'd consider raising the price of sands and oils, while lowering the price of everything else. So that people still had plenty of options for what to do with a weeks worth of Seals, but, had to hold onto them for say, 3-4 weeks in order to get a Sands.