Hmmm. Vesali's pointers are all tactical scenes, and can be different stacks in different hexes. SteveMB's scene can't be explained that easily. From the evidence, multiple stacks can indeed be in a single hex, and what the stacks are can be seen before initiating combat. My mental picture just got flipped a bit, that kind of mechanic makes it much more difficult for the game to actually be cardboard on a table.