I find that 1.5 number amazingly hard to believe unless those engineers are never actually watching the vehicles while in use, in which case the number means absolutely nothing. The number of engineers per vehicle on staff means absolutely nothing if they aren't the ones monitoring them for issues while in use. You might as well say you have 50 employees per vehicle, including all office workers, executives, janitorial staff, etc. because it means nothing.

Given videos like this where there are dozens of them in complete chaos. Human intervention would easily clear that in a couple minutes, instead they just kept stacking up.