I implemented player units and the possiblity to command them into my game Shatterpoint.
At the moment of speaking there is no possiblity to spawn them beside adding them via the Godot editor.
The units will attack enemies units and will be attacked by them, completing the last big feature of the game beside progression.
I was scared of that implementation because I thought it will be hard but in the end it wasn't.
Next step would be to add a player building where you can select units to spawn by paying scrap for them.
That's the last missing piece for my vision of the game without the progression aspect.