The outside shim will not tighten the gear mesh, it will pull the outdrive out sightly putting pressure on the sun gear shim with the pin keeping the mesh consistent. If you use the .5 shim and the outside shim, there will not be enough space to get the sun gear pin through the hole. That's why AE says no outside shim when using the .5 shim. You need to let the outdrive post move in a hair to then get the pin over the thicker than designed for shim.

Also, like Cain said... not sure what's right for you. Those gears are not exactly machined pieces so some diff builds will vary. Best to dry fit and see how it feels then run it once you feel like it's correct. If your 5k rear fluid feels like 7k or 10k, the mesh is too tight.

Almost always better to start with fresh diff housing so there is no play in the outdrive... especially if you have run it for a while.