The Palestine Mandate which included what is now Jordan was a completely artificial creation set up in the horsetrading around the Treaty of Versailles. To talk of it as if it had some kind of historical unity is absurd.

The area to the East of the Jordan had never been linked administatively with the area to the West, which under the Turks was made up in 1914 of three separate "sanjaks". See the map on this site - a Zionist site, as it happens, to avoid arguments about this being an anti-Zionist distortion.