Interesting all this info on MB training. Getting trained technicians is becoming more and more a problem.
Probably the biggest problem is that there is almost NO place in the US where any form of licensing exists. In the few places where regulation does exist only the most basic automotive testing is required.
I haven't been in the dealer loop in over a quarter century so I haven't a good idea of their certification level. I do know that I hired an experienced tech from Toyota and during his training at my shop a much less senior Toyota Tech left and went to the dealer. He started working on cars immediately knowing nothing specific to MB. (I know all this as I got periodic reports from my tech as the other guy did get to go to MB school before I sent my guy anywhere. He might strees this school issue if he had to pay any of his families Blue Cross coverage as does his friend that works for the dealer.
Anyway, strange as it may seem there is only one real certification mechanism in the US that has any teeth. Amazing as it may seem AAA is the mechanism. To be a AAA approved repair facility, one must meet many business criteria (not worth mentioning) before they do a police background check on the principles. Once these basic requirements are met they come and visit. They require an ASE certified tech for each area of the car that AAA approval is sought. With each area there are intense tool requirements (which they visibly inspect). After all this, the shop must submit 100 consecutive work orders to which AAA does a CSI report through contact with these customers. Only shops with a 90% CSI are accepted.
I'll bet you would find a bunch of MB dealers that couldn't pass the tests.
Bosch Master, ASE Master, L1
33 years MB technician