my first tutor at college when i did my nvq (about 17 years ago) was the best person i have ever seen on the tool's, he did some subby work for a few local firms and i got to see his work first hand. He was the best tutor i have ever had over the 17years i have been training and re training, probably because of his experience's and knowledge on the tools.
so as you may of guessed i disagree with the statement of s*** on the tools then teach, most good tutors are very good experienced tradesmen, if they are not then i would expect they may lack something when they come to teaching, every good tutor i have come across had good practical experience.
now as for contract mangers, site supervisors and managers many lack basic knowledge from my experiences.