Sorting cases depends on the distance and accuracy that you expect at those distances. What does it effect? Well all three because all three interact with each other. ES/SD will be effected because of volume differences between cases, which in-turn effects velocity which in turn can effect accuracy with slight vertical stringing which is further exaggerated the further you shoot. In extreme cases there can be enough velocity change to take you out of a node if your have a rifle that is riding the edge of a node as is. I used to sort cases but I quit as I usually just ring steel and normally stay 1K and in and with higher quality brass such as lapua I noticed I didn't cull very many cases anyhow. This would be an entirely different situation in something such as benchrest or F-Class where its a game of group size. I seem to find these days I make more money in ensuring neck tension is uniform and exact powder charge on all cases than weight of the case itself. Good luck brother in the rabbit hole!