read what you quoted again
In mount and blade terms it is incorrect I guess, or means the same thing really.
But I am trying to differentiate the two, basically if you prepare an attack you shouldn't be able to move with the weapon.
In the real world chambering an attack means having the attack ready to throw, since chamber blocks aren't really a real thing in the way they are portrayed in M&B.
Sorry for not conforming to the imaginary non real code of lingo.