This is what I always thought the 3-4 was all about. You rush your 3 down guys plus one other, but which of the 4 LB's rush is unpredictable. By picking supposed DE/LB hybrids, you lose flexibility and the system effectively becomes a mediocre 4-3. It can still work if some players are exceptional, but the Packers don't have any exceptional pass rushers in the front 7.
The result of bad personnel decisions is even more predictable than the Packers defense.