Some time ago I was in a practice where the team was preparing for an upcoming opponent that could have had two left handed hitters. One would probably play opposite. The other possibly at outside hitter. The team practicing had a left handed hitter, and they asked another lefty to come in and play with the scout team. It was a strange set up with two lefties in a standard rotation. The opposing team ended up only playing one of the lefties, but I often wonder if there is an effective way to play both at the same time.
As a thought experiment, I took a bit of time and looked at how it would be to put the outside hitters in zone 2 on the front row, and the opposite and setter in zone 4 on the front row. I kept the outsides in zone 6 on the back row, and flipped the libero and setter/opposite sides. This puts the left handed hitters facing the setter when hitting both front row and back row. The opposite now hits from zones 4 and 5. The real question was what the serve receive rotations would look like.
I sketched the rotations* out based on the traditional lineup ( setter in 1, outside 1 in 2, middle 2 in 3, opposite in 4, etc). They got real weird and unwieldy. The only rotations that worked out well were the ones with outside hitter 1 in the front row. The other rotations had hitters getting piled up in each other's hitting lanes, and left handed and right handed hitters hitting in the "wrong" places.
Not satisfied with that, I flipped the positions' serve order and tried again. This time it worked out. It would be a strange thing to play against, and to play within at first, but I was able to get usable serve receive rotations that are very comparable to the standard ones. There is an unavoidable rotation were outsides and opposite have to hit from the "wrong" side, but the standard rotations have that as well.
A few interesting things that became apparent with the flipped rotations. One is that a quick hit behind the setter is now the most natural hit for right handed middles. Another is that right handed setters are ideally positioned to swing for a kill on the second contact.
This setup will also be a good thing for left handed middles. Quick hits in front of the setter will be better suited to left handed middles. This makes me wonder if this is something that would only be really useful with not only 2 left handed pin hitters, but also at least one left handed middle. The unusual nature of this lineup might make it worthwhile with just the two lefty outsides. I know I would have a hard enough time trying to adapt my way of thinking to deal with the strangeness during a match. Maybe even with warning and good scouting. It would just look strange. I can only imagine what players facing this would think.
*I'm not going to include the sketches because they are ugly, and I don't think it's worth that much effort to make it look pretty.