The size definitely helps. If a GUE instructor certifies someone who doesn't meet the performance standard as intended and that person moves onto the next course doing their due diligence with number of dives and practice, it is not going to be swept under the rug. It will probably be noticed prior as the GUE communities tend to be close knit (a real positive in my opinion, they are incredibly supportive, including with people who haven't gone through their training courses, at least that is the case here in Seattle).One thing that really impressed me about GUE's system is how well they handle quality. Very much like I've experienced in an IT training organisation I wrote a course for. This requires feedback and a high level of trainer mentoring from the company.
The results are clear to see within these hallowed pages; few people ever disparage GUE's Fundamentals course. Definitely not the same high regard for all agencies.