1. Shouldn't be at altitude. He complains all the time that he feels 'bad' or 'tired' or whatever. I think this is the big one. It should allow him to do proper training.
2. See a proper PT. Dave Mchenry or whoever. Someone should be able to fix the hitch in his stride.
3. Get some consistent T work in, getting up to at least 8 miles. No Double T when you can't even control the single T. Weird coaching there. Restructure or even lower weekly mileage to allow this. Also if T is hard break it up and DON'T jog the rest.
4. If the fixing the fatigue/upping volume stuff doesn't work, join Very Nice Track Club. Warhurst has had success with runners who need long breaks between workouts and low volume (Ben Flanagan for example)
5. I know my advice works because I am sitting in my bead with a sfx