When I constructed these sand ladders, I wasn't sure how big I wanted to go with them. These are about six inches longer than the ones I typically used in Arabia. I decided to make them a bit larger in all dimensions, because I wasn't sure how and where I was going to be using them. I am planning a driving trip around the world, and so I built them bigger, because it remains to be seen the type of conditions I will encounter on the trip - sand- mud - snow etc. I can easily cut them down by eight inches of length and still have a very functional ladder in the sand. My thought was to go large, but if the length isn't need, then cut them down to lighten the load. It would be possible to have three inches less width and eight inches less length if I was only going to use them in sand. In mud or snow, a longer and larger ladder could be beneficial. So my constructed length may not be the final length. A few minutes with an angle grinder and a cut off disc can shorten them to any length.
We always used four sand ladders when bogged down in the sand since we had four wheel drive. But if a person has only two wheel drive, I see no benefit from carrying four sand ladders. That's what the large water trucks do in the sand dunes. They have only two wheel drive and so they use only two sand ladders.
I have been amazed what you can accomplish with two wheel drive in the sand dunes if you know what you are doing. Twice in the Empty Quarter of Arabia, I have seen Defenders driven in two wheel drive without too much difficulty. One Defender broke a front half shaft at base of a dune after descent down a slip face. The other Defender had a broken rear differential, and they disconnected the rear prop shaft and removed the diff from the vehicle, and it still drove around in the dunes for another week using only front wheel drive.
If you only have two wheel drive, there is no point carrying four sand ladders unless you are laying down a track in the sand on which the vehicle will drive.