I know you won't like what I have to say but it has to be said. For that, I apologize but the content is what is important.

Viking had no business saying you needed to brace anything. I can see that being said to the installer but not you.

If your sump is connected to your pool pump, set your suction so that the only suction available is to the dry well and the discharge is sent out to Waste. That will suck the water out from behind the pool wall. Using a flashlight, look in the sump. If it stays dry, you can then empty the pool. If it doesn't, the installer will have to empty the pool, not you.

I hope you don't have to pay to have new water trucked in when they are done bracing and back filling. The back fill will likely need to be the smallest gravel available as it doesn't wash away.

I hope you don't have more than a three foot apron around/over the pool holding it down and that they don't have to lift the pool. If they do have to lift it, the concrete is history. You can't lift it due to the weight and sag it would create.

This is exactly the reason why Viking doesn't allow homeowners to be the primary contractor. They have a set of rules for the proper installation of their shells. Add to it what most installers do and you will have a shell set that will last a lifetime.

Scott