Let's get together on terms here. What country are you in?
What you have depicted is called a shower are,(see image) This goes into a drop earred ell,( see image). What goes on the end is not a spout it's a shower head or spray head(see image). A spout,(see image) is what the water vcomes out out when you draw a bath. Are we clear?
The question is really: with a screw fitting, do you have to screw it all the way home
You must Teflon Tape the threads and screw the shower are into the drop earred ell until it's tight and won't turn any more.
They're not designed to swivel.
We have just installed the shower arm on the drop erred ell and now you tape the threads and screw on the shower head. That takes care of the shower arm and head. What's with those elbows you have that are 15mm compression fittings ? Where do they go? Back to you, Tom