All Seven could do was remember Borg data and adapt to weapons (which wasn't something she could always do, it took a special occasion to reactivate that power). We don't know that the Descent Borg and Hugh couldn't do the same once they studied themselves enough.
Seven had more time to explore what an Ex-Drone could and couldn't do, given enough time Hugh and co would be on her level. They're already more powerful than her physically anyways and we didn't see enough of their mental capacity to know they couldn't be as smart as her.
Seven had more time to explore what an Ex-Drone could and couldn't do, given enough time Hugh and co would be on her level. They're already more powerful than her physically anyways and we didn't see enough of their mental capacity to know they couldn't be as smart as her.