The best player I ever trained was my own draftee Blake Cates who I trained to a 127 TSP SF. Although I've had and currently have NT players on my club team I've never trained one from start to finish.
I agree that it's ideal to have a coach who runs a program over multiple terms. If elected I hope that will be the case for me. At the same time it should be understood that if you're doing it right a coach will likely burn out after a couple terms (a full calendar year). I know I did previously. My though is it would be disingenuous for anyone to say up front they'd do more than two terms.
Although his term ended on a bad note, prior to that Sahand did many things very well. He personally handled a huge number of trainer contacts, had a good understanding of NT strategy, and got us an American gold (which is no small feat).
Unfortunately he was a bit of a poor fit in the end despite this. I think mainly because he was not used to collaboration in this game, which let him to handle manager contacts all himself, he did a poor job communicating any planning to the larger community, and he made some tactical mistakes during Worlds which might have been avoided if he had encouraged more planning involvement with the offsite.
But no one is perfect. I'm not going be either no matter how much I'd like to think I would be. What I would do differently is just to try to get more involvement from others. Have guys who will scout some ages classes, create an environment where it is easy as possible for someone on the offsite to have enough information readily available that they feel they can contribute informed opinions on strategy and tactics. It's easy to get tunnel vision, if enough people get in on the discussion I can make decisions that are as fully thought out as possible.
I (or anyone else) don't know what Sahand told managers of potential NT players beyond the base 1v1F training. So I don't know if this is different, but I would love to encourage a variety of player types if I can so that in the future there are legit options for multiple tactics. This is probably what anyone would say, but hey, it's from the heart.