This is very easy to do with hierarchies and templates.
Create all your hierarchies on a separate "Assets" layout. Select multiple objects, right-click the parent sprite and choose "Hierarchy - Add selection to this instance".
Then in properties on the parent object set it as a template and give it a template name.
Now when you create the parent object, you can specify which template to create it from, and if you tick "Hierarchy" textbox, it will be created with all its children objects.
In your case you can use an invisible sprite as parent.