I’d drop the push press as well, that’s more of an advanced exercise that I wouldn’t progress to until he can safely and effectively overhead press. It’s likely that he’s going to be fairly sore at first so you might need to appeal to his vanity by including something like bench press to get him invested.
Yes I can see it being difficult for a novice. Although some people can pick up even oly lifts relatively quick. I didn't consider that seemingly simple movements can be daunting for some folks. Dunning Kruger in effect. I might suggest just a 2x per week to start and progress to 3x once he gets adjusted to the effort, patterns, DOMS, and the like.
I don't agree with you, having been in the military and knowing that approach does not work very well. But I will chalk it up to having different experiences than you which have shaped my viewpoint differently than yours. Generally the conservation of energy comes in the relaxation phase of use with technique that only comes over time. Until a fighter learns how to relax, he will burn up energy regardless of technique.
I don't remember specifying which part of the workout that I was talking about so please, do not write sentences for me that I never did in the first place. And I never mentioned anything about stopping training... so ya know what, you can give this guy all the advice you want. I'll just be over here..
You specified slow twitch, which one can only assume relates to the squats, deads, push presses. Thing is when you do lower reps with the intent of moving the weight fast (as seen in training for explosive strength), regardless if the load forces you to be slow, you recruit the necessary fibres. If that type of training truly forced an athlete to be tight and slow, Olympic sprint events would be full of waddling ducks. It's not mass/hypertrophy goal oriented.
Technique is exactly that, the firing and relaxing of muscles at the appropriate time. You don’t learn how to relax, you learn movement/technique.
It seems you know enough already to be an asset to your relative so perhaps the best advice is are you able to do this work with him? IMO with people who have not had a strong sports background, physical activity that they can do with a family member is more likely to stand the test of time than them doing it by themselves.
Unfortunately we live hours apart. Even if I was able to, it would just be a couple shadow days of running through the workouts and giving tips/cues on the patterns and techniques, and answer any questions that may come up during the progression. I train strictly for hypertrophy at this point, but started with sport specific, so all I could offer is a run through. Ultimately it's on the individual to maintain a consistent effort. They either want it or they don't.