can understand why for the purposes of this thread you'd want to just focus on Islamic, but why would you limit yourself to immigrants of mideastern / S.Asian origin?
That would exclude for example all of the 7/7 bombers and all of the terrorists* responsible for the attack at Glasgow airport (i.e. basically most of the terrorists who've actually done something in the last 5 years)
If you did just limit it to Islamic, then i think the conclusions of the report wouldn't have been significantly different, judging from the wording in the
article it very much sounds like the MI5 report is focused on Islamic extremism, which would make sense as AFAIK its the major terrorist threat to the nation.
(*assuming India doesn't count as S. Asian, if it does then one of the terrorists falls into your category)