We could let tileset author to define the upkeep icon placement with an alternative way, telling how much they are to overlap with the unit icon. Currently unit_upkeep_offset_y is applied from the top of the unit, so some calculation is needed to figure out how tall the unit is, and then to subtract wanted amount from unit_upkeep_offset_y. This alternative syntax would be indicated by a negative value (as it tells how much to subtract relative to unit bottom).
We could let tileset author to define the upkeep icon placement with an alternative way, telling how much they are to overlap with the unit icon. Currently unit_upkeep_offset_y is applied from the top of the unit, so some calculation is needed to figure out how tall the unit is, and then to subtract wanted amount from unit_upkeep_offset_y. This alternative syntax would be indicated by a negative value (as it tells how much to subtract relative to unit bottom).