A nice piece with Allan Lamb in the new Wisden Cricketer. Asked 'what made you so successful against quick bowling?' he replied: 'I had a technique that worked. On quick wickets against quick bowling, you don't get in behind the ball because, if it lifts a bit off a length, how are you going to get out of the way? You stayed inside the ball so you could cut, or outside so then you could pull. You had to duck or play, there was no fending on bouncy wickets.
'Against the really quick bowlers I would watch the wrist. Sometimes you could see the seam, and the quicker the wrist came down, the shorter the ball was going to be. That was vital. I didn't love playing against them but it was always a challenge'.
There is a huge amount of truth and insight here [yes, from Allan Lamb...], perhaps most of all his thoughts at the beginning and the end of his answer. The measure of a technique is its effectiveness; the reality of quick bowling is that no-one likes facing it [and speed is relative to ability, so the feelings it invokes are universal].
The detail of Lamb's technique, as described, is not textbook. It sounds more like Phil Hughes than Geoffrey Boycott. That's why technique cannot be applied or evaluated equally to all. Boycott, for example, or Atherton, were rather good at fending. It's an individual thing.
It's also why Peter Roebuck's otherwise well-wrought argument over the 'nonsensical' changes in technique for T20 cricket is not quite convincing. Technique, to me, is like language. It is not a static thing. Rather, it's alive and vital, always being added to and adapted as well as used classically. To draw a rather gallumphing allusion, we no longer speak like Shakespeare, but the beauty and rhythm of his language retains all of its power.
No-one bats like Grace any more, and perhaps only Dravid leaves the ball like Boycott, yet technique is as alive and as mutable as it has ever been. No single player will encompass it all. The key will be the same as always: to the fit the relevant parts to what you're trying to achieve.