The criteria for movement at the pinnacle of the men’s game is strict. Only that which is necessary should be encouraged by coaches. Anything below high intensity will not prevail and to sequence all of the different movement criteria together in one continuous motion is the goal.
The personality or attitude of the athlete will need to be aligned before potential success can be imagined. In my experience it is more beneficial to build the personality before realising technical competence although both paths to excellence have been seen in the past.
There are parameters of excellence which you must fall into otherwise reaching the top will not be possible. In the women’s game currently the overall criteria at the top is broader than the men’s but over the last few years – as the professional era gathers momentum – the scope has been narrowed considerably and in time it will be equally as hard to be at the top of the women’s game as it is the men’s.
When you watch juniors play it is obvious the commonalities aligned with success, by and large less attention is given to technical expertise and more emphasis is placed on the enjoyment of competition but as you go through the juniors into the seniors and climb higher you notice how each movement and swing seems to shrink into a uniform pattern. The different angles of the body and racket bunch closer together at the very top. Any bad action in comparison will be obvious and any superfluous effort will ensure the onset of fatigue and the pitfalls it carries.
This is not to say that styles will not vary only that it must fit somewhere within the world class parameters. As it is a combination of different attributes a player may be able to balance this criteria out by being exceptional in one area to counter another weaker one, however the mean score must reach the world class level in total.
Those outside these parameters will need to make the necessary changes for however hard they try the results which will take them to the top will most likely elude them.
The world rankings are devised to reward consistent performance over the year and subsequently this is how the top players approach their daily work. However, there are many players who train to win a one off match in favourable conditions which often explains why they are beset with inconsistent performance.
This is why building the personality of the athlete from an early age can be fundamental to them achieving their long term goals. Reaching the top takes certain characters prepared to go through years of analytical, dedicated work with plenty of soul searching in the quest of becoming world class.
Peter Genever 
I see your point, however, I think there will always be some room for something radical. Peter Marshall almost made it to the top with his two handed backhand. Had it not been for Jansher Khan at his peak, Marshall probably would have reached #1.
Peter Marshall did make it to number two in the world and he was definitely within many world class parameters. He was a brilliant, unique and courageous player. His career was unfortunately plagued by illness and so he was unable to sustain his ranking at the top although he made at least two journeys to the top ten during his time.
I would say that from an efficiency point of view he was probably at an unsustainable level for the top ten. His unique style of playing two handed was used on both the forehand and the backhand, with his dominant (right) hand at the top of the grip. He would release the bottom hand upon impact on the backhand side but would mostly keep his bottom (left) hand on the grip throughout his forehand swing. This means that his position would need to be closer to the ball to swing comfortably and this makes the court bigger. Every movement required him to go further into the court than other players and he always did this with great intensity. In addition to this the racket heads were miniscule and the scoring to fifteen points. It took a monumental effort to keep this style of play continually competing at the highest level especially the way Peter pushed himself physically in every match.
He would only adopt a one handed swing – predominantly on the forehand – if under extreme pressure (or to serve) and would only really “push” the ball this way with the lob, lift or drop. All power was generated with the two handed swing.
It is not for me to say whether this contributed specifically to his illnesses but there is always the possibility that extra physical work, coupled with intense training could lead to the dangerous depletion of energy over time. This scenario may have a bearing on a person’s health.
So overall, maybe some room for radical but perhaps not with longevity?
Agree with your points. don’t post obviously, but criterion – singular, criteria – plural 😉