Personal opinion here based on one real life situation....

If a pack shorts then don't bother about having a redundant one. I had a freshly charged pack short on the bench. By the time I got it outside the covering had burnt off and the cells were venting and smoke was pouring out. If I hadn't cut the cells apart immediately (not knowing where the short was) I would have expected a fire or something very close too it.

Now, if that shorted pack had occured in flight the plane would have never survived even with a redundant pack. It would have burnt badly or caught on fire entirely before it got to land.

Dual switches, diodes or whatever would not be of any value with one pack having a dead short. As for a pack having a bad cell or whatever, then it's going to help you but then you have to be checking voltages between each flight to pick up on the failure.