My issue is that ordos don't really use beta cores that much. After you kill a few, they are mostly alpha cored. Another problem is that lower tier cores tend to be used in smaller ships, and smaller ships have lower chances to drop their officers. Does the difficulty scaling drop back down over time or not?
Edit: speaking of the explorarium, do probe defenses ever get beta cores? I was under the impression only survey ships get betas, which makes them very rare indeed. What about derelict bounties?