Well that's too funny... I was going to post that very suggestion, but unfortunately I lost track of this post and never ended up replying.
¯\_(ツ)_/¯.
I think your new approach is a great solution.
Hauling in fill is much cheaper than building the wall across the back and will give you a better end result. This also works much better with the pool dig. If you want to do it in phases you can now leave enough space to accommodate the excess material from the pool dig.
I would also consider putting some blocks in front of the shed and along the Gable end that's sticking out of the ground. So the top of the blocks is just below the floor of the shed and flush with finish grade. You would then step out of the shed onto the top of the blocks. this will allow you not to have to try to backfill under the shed and leave a good air space under there as well.
¯\_(ツ)_/¯.
I think your new approach is a great solution.
Hauling in fill is much cheaper than building the wall across the back and will give you a better end result. This also works much better with the pool dig. If you want to do it in phases you can now leave enough space to accommodate the excess material from the pool dig.
I would also consider putting some blocks in front of the shed and along the Gable end that's sticking out of the ground. So the top of the blocks is just below the floor of the shed and flush with finish grade. You would then step out of the shed onto the top of the blocks. this will allow you not to have to try to backfill under the shed and leave a good air space under there as well.