It is very frustrating when applying an arrowhead to a stroke when you don't know what InDesign calls the start or end of that stroke. It's not so bad when you've drawn a straight line but a number of times, we edit shapes to create complex lines. Then it's a case of trial and error as to which end you place the arrow (and most of the time, typically, you end up choosing the wrong end. I know there is the ability to swap these but it would be useful if when you hover over either the start or end drop down boxes it would highlight which end of the line you're going to apply the style to.