Once the Queen had some drone out in the depot fedex their zombie asses to her bedside to become her new yeomen?
But the two years before Dark Frontier or the two years after Dark Frontier?
So what if they couldn't get the Flesh, why didn't Seven just take copies of their personalities from the collective gestalt?
We have to assume that digital copies of minds go in and out of drones all the time to see about business of the collective, and when a digital copy makes contact with a flesh mind they update each other on their personal adventures... So that any real mind etched into the meat of a living brain is full of so many digital experiences that it is just as fake as a digital impression of a mind wandering about in a server farm.
Seven said herself that early versions of herself still live on inside the Collective and work towards the Borg ideals of achieving universal perfection... Of course unless she was firewalled by the Queen, Seven who played out the Voyager experience, then after during Dark Frontier would have updated all earlier models with a lust for individuality to varying degrees of success.