Great Q and observation @StuartMcMillan1 And as requested @Richwheater here's my quick thoughts: On Amos, and on running technique in general.
If we persistently practice in a healthy state --not injured; not overly fatigued; not in continual discomfort-- we instinctively learn to run efficiently & robustly. What efficiency and robustness 'look like' when we run varies, dependent on the combination of all our individual architectures --muscles; joints; bones; tendons etc.--, idiosyncrasies and injury histories.
So, for me, if Amos's tech is ugly, i.e. it doesn't fit with our conventional vision of how running 'should look', personally I wouldn't be overly concerned BUT, as with any runner, I would be constantly on the look out for subtle signals (emerging hotspots; repetitive tightness's and localized fatigues etc.). AND, again as with any runner, I'd suggest specifically targeted on-going training to optimize coordination; stability around joints; postural control etc.
In a nutshell, running isn't artistic gymnastics: we don't get points for conforming to notional visual ideals. Instead our brains and bodies have evolved, over millions of years, to meticulously shape how we run around our uniquely individual neural and biological characteristics.
But... The complicating factor is that, sometimes, a technical quirk can actually be indicative of increasing vulnerability, or decreasing efficiency.
So.... like many other questions in the coaching and conditioning world, there may not be a 'right' and a 'wrong' answer: no easy answers, no simple solutions.
If I was to pretend to be wiser than I am and try to synopsize my position:
-- Perfect technique is an individual solution, to an individually unique problem. Don't tell the athlete 'how' to run, help them explore different solutions by designing progressive training challenges. AND don't panic if they look like a bag of coat-hangers rolling down the track -- is there style consistent? How does it change under fatigue? Where do hotspots first appear when they fatigue?
The great coach and exercise physiologist Jack Daniels once sent video of 20 competitive --previously physiologically-assessed-- runners to a selection of coaches and exercise scientists, asking them to —on the basis of visual inspection— rank athletes in order of running economy. After the results were analyzing, Coach Daniels summarized his findings, saying, “they couldn’t tell… no way at all”.
(This certainly doesn’t qualify as conclusive evidence, but is interesting nonetheless).
Is Amos inefficient and 'at risk'? Would he benefit from changing his running style? Or is he yet another example of an exceptional self-organized, self-optimized, but non-conventional, runner?
Pay your money, and take your choice.
…. For now, my money is on the latter.