Different Mouseover Stack Viewers for different units

My module has two kinds of units - headquarters and “other”.
Each “other” unit has an ID Property; each Headquarters unit has a Supply Points property.
When I move the mouse over a stack, I want the headquarters units to show their Supply Points values, and the “other” units to show their IDs.

I tried assigning each unit a Property called “IsHQ”, with 1 for headquarters units and 0 for others units, and then having two Property-based Mouseover Stack Viewers - one for “IsHQ=0” that shows $ID$, and one for “IsHQ=1” that shows $SupplyPoints$.

This works the way I want - unless a stack has both headquarters and “other” units, in which case the headquarters units appear over the other units. (For example, if a stack contains HQ 1 and units 2, 3, and 4, then the mouseover stack viewer displays HQ 1 (with strength points) and units 3 and 4 (with IDs), but unit 2 appears to be hidden behind HQ 1.

Is there a way of doing this such that all of the counters in a stack will show up?