Is there a way if you have a parent unit (one counter), and when you right click on it you can break it down into say three sub-counters (children) or build the parent counter back up from its children?
For a simple case of unpack parent / re-pack children:
Parent: Trigger Action provides the menu command “Break up”, that does a Place Marker for each child piece and the deletes itself.
Child:
Trigger action provides a menu command “Make up”, that does a Delete on all other child pieces from the game (use a Global Key Command that excludes the current piece). Finish with a Replace with Other, restoring the parent piece.
You could develop the parent action further to allow the parent to shed child pieces one at a time, keeping a count on the parent piece of how many child pieces remain. In this example, child could be re-united one at a time.
Drag and drop functionality could be added - for dropping child piece into the parent - by using a Trigger Action from the Map movement key command.
If the pieces all have be in the same space/hex to combine, you could also set Restrict Range to 0. This would be especially useful if there might be other, otherwise identical, pieces elsewhere on the map.
In addition, setting Within a Deck, apply to to No Pieces will speed up processing (as the target pieces in this case should never be in a Deck),