It might be assumed effective techniques were developed in one single generation. I imagine it to be a constantly evolving process.
Think of all the adjustments, tweeks, deliberate and/or consequential changes to a technique over several generations of acually using them - full power, full force, intent to kill in a war setting. It's a very different mindset that I only know enough to realize I can't even imagine about. As passed down, each generation wants to give their next the best of what they've learned and improved upon. next gen does the same and so on.
Your tounge in cheek example is not so outrageous, but the timescale spans over centuries not a single battle. If you look into the fairly well documented history of the development of warfare during the middle ages in various parts of Europe, you'll see how weapons/techniques/tactics progress in blended stages.
H2H development should be no different- I think it's reasonable to assume it develops along the same learning and adjustments curve in any part of the world....the needs dictated the skill. The needs were to defeat as fast as possible.
Melee combat on ancient battlefields is a fact. people East and West DID fight with swords at one time...they DID need to know how to kill someone in the quickest amount of time to lesson chances of being skewered from behind as oppossed to trying to 'tap' their opponent out on the ground.
If history is not ignored, it is a certainty that men in all 'civilized'
societies had training methods and a knowledge base of methods.
I believe in it's beginning stages, efficiency of training those methods of quick killing was formed into kata as a recallable and consistant training tool.
The methods and needs of the warrior gradually changed with technology...calling for less and less H2H for military purposes...meanwhile, some ex-military guards employed to protect a temple or castle (still talking generically East or West), incorporate their training, but choose not to train the battlefield murder-moves and instead focus more on defense, control and restraint...and perhaps even methods of non-lethal crowd control. Of course they still trained and passed on the battlefield knowledge, but maybe it gets transfered to less and less people after each generation.
More centuries pass with kata being reshaped along the way to the needs of the people in occupation to use them as a training method.
Eventually, kata goes thru another revolution of changes, this time with civillian self-defense in mind. The people using and training this way, over time, over generations form the practice of kata to their self-defence needs.
In the line of thinking that I'm following, Kata went thru yet another series of 'adjustments for the needs' when introduced as a fairly safe practice of physical fitness and rudamentary skill building to the teenagers of well-off families in schools which were more than likely destined to become officers/soldiers during the first high-technology driven war...WWII. The history from there is more or less documented.
A possible way I see kata developing into, is for a practice of well-being, moving meditation, perhaps even 2-person moving meditation. The threat, to justify inordinate amounts of time practicing self-defense, is just not there for most people in suburbia during the 21st century. A bit of street smarts, awareness and technology(cell phones, protection devices,etc) is sufficient enough for more than most.
If kata practice moves that way for the mainstream, fine ...but it doesn't need to be justified by ignoring kata's original very probable battlefield intent.
It's almost like people need to justify in their minds what they do, even if that involves ignoring sensability.
I understand the motivation...the market is heading towards well-being, not self-defense - whoever comes up with a good sounding theory as to how and why kata should be practiced for well-being, gets to open the first book and gym-chain. going a step further to seal the deal would be to come up with a theory of kata's original intent of well-being...eons ago...predating it's Martial training use. It's romantic and it would sell. Actually, I'd like to believe it myself - it would give a nice 'full circle' in people's minds on the history of kata practice.
It's not a bad thing...everyone has a right to make a living. It is what it is.