Personally when I tried mentoring I just facepalmed. Some people just can't be taught, and from my experience that applies to approximately 90% of tribalwars players. I mean most players are entirely casual; they are here to kill time and occasionally kill something, maybe make a new friend or two but they really don't care about how the game works and becoming better. E.g. one guy I was mentoring refused to build rams for 'speed attacks', I pointed out nobles were slower than rams. He just reiterated his 'speed attacks'. Tried explaining why rams were useful, gave him quests to build them but his 'speed attacks' were more important. I showed him simulations showing how rams were useful but nope. People like that don't want to learn. There's also the large issue of a significant proportion of mentors being fairly poor players, I mean it isn't really particularly selective as to who can become one as far as I remember.
As for teaching tribes, I'ma go out on a limb and say there has never been a good teaching tribe (that I know of anyway). The one I think mr nauzhror thinks is good, really wasn't a good teaching tribe. 300!!! was not a bad tribe, but pretty much all I picked up there was an incentive to be more active. There was nothing really new there I hadn't seen before (well with the exception of PP's lightening startup guide, which was just a rigid build order so being told to do something rather than learning why). I didn't leave the tribe as a particularly good player, in fact I was still quite bad, but I was now capable of top 20 starts because I realised the power of activity. I didn't build good accounts, I didn't plan ahead and I certainly didn't think much at all. (Waiting for someone to say I still don't). I don't think that's a success. I guess teaching tribes probably function better than a standard 'noob' tribe, but that's about it from my experience (and what I have heard from others who have been in other teaching tribes)
One of the main reasons most teaching tribes don't work is this game is about adaptation and thinking, which isn't something teaching tribes have historically tried to do. They just teach you what their teachers think is right in certain circumstances. If they are somewhat competent they might discuss alternatives with you explaining pros and cons, but most players (and this includes 'teachers') are quite rigid in their play style (although at the same time they will claim versatility via one unit, HC) and that just gets passed on to the students.
The education of new players not working comes down to two things: most people don't want to teach properly and most people don't want to learn properly.
