If you don’t want the pieces stacked, you could instead add a Rectangular Grid to the Scrap Yard map, and then use the “Grid Location” option of Send to Location (instead of using zones), along with a Global Property (GP) per player to track how many units have already been sent.
So, the destination of your Send to Location would be something like {(PlayerSide == “Axis” ? “A” : “B”) + (GetProperty(PlayerSide + “DestroyedCount”) < 10 ? "0" : "") + GetProperty(PlayerSide + “DestroyedCount”)}, assuming you have two player sides, one of them called “Axis”, and define your Grid Numbering to use a single letter for the row followed by 2 digits for the column (this will break if more than 100 units could be destroyed for a single side; a more complicated formula could be used to allow for more units).
You would also need to replace the Send to Location with a Trigger Action, which would call the existing Send to Location, then call a new Set Global Property trait, set to modify {PlayerSide + “DestroyedCount”}, to increment it by 1.
If you have more than 2 sides, the Send to Location expression is a bit more complicated: `{(PlayerSide == “Side 1” ? “A” : PlayerSide == "Side 2" ? “B” : PlayerSide == "Side 3" ? "C" : "D") + (GetProperty(PlayerSide + “DestroyedCount”) < 10 ? "0" : "") + GetProperty(PlayerSide + “DestroyedCount”)}, for example, if you have 4 sides.
If you want to put different types of units in different rows, it gets even more complicated: `{(PlayerSide == “Axis” ? (UnitType == "Infantry" ? “A” : UnitType == "Armor" ? “B” : "C") : (UnitType == "Infantry" ? "D" : UnitType == "Armor" ? "E" : "F") + (GetProperty(PlayerSide + “DestroyedCount”) < 10 ? "0" : "") + GetProperty(PlayerSide + “DestroyedCount”)}, for example, if you have 2 sides and 3 types of units.
If you would rather have a separate Scrap Yard map for each side, you would could create a “Scrap Yard” map for each side, named (for example) “AxisScrapYard” and “AllliesScrapYard”, then set the destination Map in your Send to Location to be {PlayerSide + “ScrapYard”}. That would then simplify the location part of the Send to Location.
Warning: I’m typing all of this without actually testing it, so there may be some syntax or logic errors!