This is a really minor bug or (possibly intentional feature).
When looking at a stack of units on the map (not with the stack viewer), you have a stack shown as
A (top of stack), B, C, D (bottom of stack)
The stack viewer appears to display things in reverse order
D (leftmost), C, B, A
So how the counters order in the stack viewer is reversed from the counter order on the map.
At least how my mind processes information, the most important thing is either 1) on top or 2) leftmost. So seeing it reversed bothers me. However, this is also likely due to the fact that my language is English (read left to right). I wouldn’t be surprised if that paradigm is reversed for people whose language reads right to left.
Minor and we can certainly live with it, but still appears to be a bug… Alternatively, may it would make sense to let a player configure (as general option) if they want the stack viewer to work left to right or right to left?