I think this has been mentioned before, but it is really annoying that when there are multiple forces in a region, the highest ranking one appears on top, potentially hiding much larger forces commanded by lower-ranking generals. It means one has to mouse over every enemy stack and carefully read the "also in this region" part in order to know where their armies are. The most common example is when an army commander with just army support troops (HQ, supply, etc) is in a region together with one or more subordinate corps, but it can happen and have an impact at every level of scale.
I would strongly suggest that the number that appears at the bottom of the icon showing an enemy force is the total strength in that region, or at least the total non-moving strength in that region.