There is always the option for the in-game LFG, which thankfully works. I ran it a few times this weekend just for the flakes, and they populate fairly quickly even with the lower population. That said, it still should never be required for the story which is one of the worst decisions they made regarding new Exotic Missions. Running the same activity again and again as part of the narrative is horrible. It makes zero sense to explore the same area 4 times before finally finishing the narrative, fighting the same enemies or slightly different enemies, nor does it make sense for the enemy to do the exact same failed strategy.