When crafting items like iron plates from iron ingots, if there are multiple stacks of iron ingots in the player's inventory, the game could use the smallest stack first. For example, in game right now I have three stacks of iron ingots with 2, 5, and 72 in them (yes, I forget to sort them :P). When crafting iron plates, it pulls from the stack of 72. However, if the game pulled from the smaller stacks, it would clear up spaces the player's inventory faster. There are a couple niche circumstances where, if the player's inventory is already almost full, this could also allow you to craft more items without having to sort them first.