I would think he needs more rest. A 12 mile hike/day is going to do a lot for his conditioning but also make it harder to recuperate if he's overdoing it. While undertraining is no good, training harder/longer cannot guarantee victory. Overtraining to some extent is common, but tough to prevent.
Limited strength work at 3-6 rep max and lots of mat/ring time. With exception of swings, I would limit the higher volume or eliminate it entirely and replace it with isometrics for speed.
I cannot imagine any need to add burpees and other metabolic smoking drills on top of jumping rope for rounds or just hitting the mits/pads and ground work.
Also, including some meditation practice might be priceless.
Disclaimer - I have never competed in the ring aside from boxing matches on my street as a kid and wrestling in HS. But I have friends that have, some I helped prepare (though I was NOT "training" them) and have attended a few amateur bouts where I took a lot of notes. On average, the biggest killer winds up being loss of focus or awareness and inability to execute with good timing, rather than a collapse of conditioning.