it depends on the case, for example the soldier bar, if its has a fixed size then there is no purpose in creating multiple nodes for dividers etc, you just make one background image for all, then you place those background less nodes to capture events, you may use the model's for that but they has different size consideration for best looks, so here you go.
or if the ammo will be shown as part of the weapon node and not separate nodes, so the only way for me to capture clicks and provide different tooltips for weapon and ammo is to place 2 buttons background less buttons above it.
or if you just think it pointless to make tooltip's for the soldier selection mini bars(not main) because they are too small, you can place one above the whole and give general description
etc, everything has its use, its all depends on what you need...