Suggestion: Daily A/B Elite Hunts; Weekly S Elite Hunts. No Mark = No Credit.
My suggestion for "The Hunt".
Have Daily A & B Elite Hunt Marks and you must have the mark to get any credit, possibly even to engage the Mob you must have the Elite Hunt Mark key item. These Marks should be random for each player so players with same marks can group up.
Leave the S Elite Hunt Marks as a Weekly Mark (since they only pop every 2-3 days anyway?) but players must still have the Elite Hunt Mark key item to get credit and/or to even engage the Mob. These Marks should be random for each Grand Company so there would be 3 different hunts each week.
If an NM pops that no one has a Mark for, then it could be an open free for all.
My thoughts anyway...what say you?
p.s I realize this defeats the "Open World" nature of the hunts but it's causing too much grief imho.