Not sure how close what OP did was to the traditional Michigan workout, but I think I added up that it was 5 miles of 10k/threshold, with plenty of walking or standing rest in between.
What exactly do you find so egregious about it?
It's just another way to get 5 miles of CV --> to threshold pace. I would feel comfortable giving this to any kid I had working between 40 and 50 mpw, with a typical quality density of around 20%.
The real Michigan is a bit tougher than this, so it's good to see that it was likely modified to fit within the parameters of what OP is capable of.