TBMK- No, Not using the Star Rating! Only by your selection method you decide the 'topmost' image-
When you select several photos to create a Stack- the 'Most Selected' image (The one with the brightest white border) will be the 'Topmost' image that shows when the stack is collapsed.
Before you Group Stack- if you have several/many images selected: Clicking the mouse on one image (not a border) will make this image the 'most selected' and hence the 'topmost' image when group is collapsed.
When you expand a Stacked group (to see all images) you can change the 'topmost' image from the [Right-Click] menu: Stacking > Move to Top of Stack.
You could- Set the Grid view SORT ORDER to "Rating" before you stack, and it might be easier to select the 'topmost' image to be the 'Most selected'. (What if they are all 5-star? 🙂 )