the 10th legion Fretensis–Antoniniana in Jerusalem

[Nathan Ross]

resettlement of the 10th Fretensis Legionnaires... since Hadrians cross island wall was nearing or completed

Stil not sure where you're getting this from! Was it in a novel or something? X Fretensis were never based in Britain, so there was no need to 'resettle' them anywhere. You might be thinking of the governor of Britain, Julius Severus, who was sent to by Hadrian take command in Palestine during the Bar Kochba revolt.

It seemed probable that there might have been an unusual settlement of RA veterans in the very mountainous area of Abruzzo

Why would this be? Mass veteran settlement was a Republican practice; under the empire legions were standing formations and were not disbanded and settled together. (Stephen Dando-Collins thinks otherwise; he is pretty certainly wrong).

Irish conscripts who joined the RA in Briton ... march the "bad guys" legion and legionnaires to Spain for permanent reassignment in that place... remove the Xth legion to Jerusalem... while marching back to Rome and Jerusalem.

Ireland (Hibernia) was never part of the empire, and legionaries needed to be citizens, so there were never any Irish 'conscripts' in the Roman army.

I don't know of any legions sent from Britain to Spain: VI Victrix was once based in Spain, before moving to Germany and then to Britain in Hadrian's era. IX Hispana was presumably in Spain at some early date, and later in Britain.

X Fretensis was based in Jerusalem itself after AD70, so there would be no need to 'remove' it there. Imperial legions did not march back to Rome - they remained in (usually) permanent garrison on the frontiers, often remaining in the same place for centuries. Detachments of various legions were often sent from one frontier to another to participate in campaigns, and sometimes entire legions were reassigned in this way, but they did not travel via Rome.