That 42/1500 number is somewhat misleading. First off, 1500 is the number of Authorized employees company wide - only a fraction of those are involved with the MAX. Second, as 9 lives notes, many of those are involved in relatively mundane tasks - conformity inspections, paperwork approvals, etc. - stuff that is pretty much black or white and doesn't require much judgement. The number of "Authorized Representative" - AR's (the delegated equivalent of a Delegated Engineering Representative or DER) - the engineers that can make findings of compliance with the regulations - is less than half that number (when I was there the number of AR's was around 500 - 600: it may have gone up since I left but it's certainly not 1,500). For the most part it's those ~500 or so ARs that overseen by those 42 FAA types.
Loma - one of the things that shocked me when I read that article was that the FAA delegated all the safety analysis for the MAX (at least for the flight controls). I did a number of projects - including two new "minor models" (747-8 and 767-2C) and I never had a safety analysis delegated - they were all FAA retained and required at least 3 months prior to the planned first flight (and I know the FAA read them because they asked me questions and for clarifications on the analysis's.)
All that being said - I saw some major flaws in the way the ODA was set up - the biggest being that the ARs were never supposed to contact the FAA when unsure about something. I could respond to FAA queries, but wasn't supposed to 'cold call' the FAA. When we did what was supposed to be the final certification flight test of my system on the 747-8, we had an unexpected result (long story - but turned out it wasn't my system at fault). During the post flight, the FAA pilot asked me to let him know what we found when we investigated the anomaly - I responded "so you're asking me to call you". He gave me a funny look, so I said "just say yes". Now he was really confused - then the FAA analyst who'd also been on the flight told him I wasn't allowed to call him unless I was responding to an FAA query as part of the ODA. The FAA pilot was aghast that I couldn't simply call him to talk, but immediately said yes, 'Call me and let me know when you figure it out'...
Dumb, dumb system.