GameObjects in a list variable don't show up correct in the hierarchy

For background i am making a space imperium game with planets and fleets. I have a GameObject Fleet that has a FleetScript.boo component. This FleetScript.boo has a

 [SerializeField] fleetNumber as int    
 [SerializeField] startFleetShips as (GameObject) = array(GameObject, fleetNumber)

that i am forced to use since lists don't show up in the inspector and i want to add ships to my GameObjects fleets before game start. So to this startFleetShips array in the inspector i add lightAttackShipPreFabs.

In the Start() function i convert the startFleetShips to a List so i can add and remove ships and use more functions. But when i create GameObjects with the code

 fleetShips = [Instantiate(item) for item in startFleetShips ]

these gameObjects appears in the Hierarchy as independent GameObjects instead of children to the Fleet GameObject.

When i do fleet combat it all works, when i destroy a ship the correct ship gameobject dissapears. But it is just that the ship GameObject don't appear visual in the Hierarchy under the Fleet Gameobject which i think it should. And this is a problem becouse it gets visual messy if the ship GameObjects can't stay under their Fleet GameObject in the Hierarchy. With lots of fleets i am gonna have the Hierarchy spammed with ship GameObjects.

Any ideas?