Interested in Language
I'm always confused when I write such sentences:
They all are humans.
They are all humans.
We all should go.
We should all go.
You all may leave now.
You may all leave now.
Somehow I prefer the 1st versions, however, this small video proves (says) the opposite:
YouTube - Everyone Gets Dumped
'We should all go' - a suggestion that everyone should go
'We all should go' - the same, but explicitly ruling out any exceptions
With 'you all' the picture is confused by the use in some variants of this as an informal 2nd pers. pl.
Incidentally, the clip doesn't doesn't prove you wrong; it gives a couple of counter-examples.