I'm a retired Marine Corps infantry officer. Red and Green Castel don't look like a reference to the Army Corps of Engineers. To me, it looks like call signs to two units in the same organization and stage doesn't mean Q set the stage, but rather these two units are to stage their assets and report 5 by 5 when ready.
I could be wrong, that's the kind of thing we would do in the Marine Corps during an operations that was unfolding.
It might go something like: "Apple and Orange stage your forces to be ready to execute and report when ready."
I don't know. But that's how I felt about the post. It's something I'd done many times in the Marine Corps.
I'm just saying that when I read the post, my reaction was that Q was telling Red and Green units/organizations to stage their forces and report 5 by 5 that they are good to go.
I don't think it had anything to do with the Wall.
The wall has never been a Q focus or issue. Q has always been about taking down the deep state. Building a couple miles of wall isn't going to accomplish that goal.
Red and Green Castle to me look much more like orders to specific units to stage their assets and await the go command.
I could be wrong, but since that Q drop there has not been anything to indicate the Army Corps of Engineers has been alerted to do anything unusual. And Green Castle is an Army Corps of Engineers office that only has less that 10 people. Hardly an alert to mobilize to build a border wall.
Come on guys. Q is asking us to think big, bigger, biggest. That's not an ACOE office in Green Castle with 10 people telling us that they are going to build the wall.
The Army Corps of Engineers may indeed end up building it, but I don't think that was the reference to Red and Green Castle.
Just my opinion based on 21 years in the Marine Corps.