I don't think that this is correct, ADVO takes more time for processing. You may have the usual cases about 1 out 20 people getting there process dont fast than the others but in my opinion can be generalized.You are absolutely correct. I also have noticed Indians & Pakistanis workin in the Middle East with Visa Office of Abu Dhabi get things rolling faster & receive PPR in approx 45 days.
I remember in Mid-2016, Work Permit processing time through ADVO was 39 weeks where as the same from NDVO was 10 weeks. Currently it is 22 weeks (ADVO) vs 9 weeks (NDVO).