Have you heard about Nuremberg trials?

Those were after Germany's defeat, and those put on trial were no longer active combatants.

I'm pretty sure no military in history has ever delayed taking out an active threat in order to conduct legal proceedings. They don't need to, because enemy combatants don't have to be guilty of any crimes to be valid targets under IHL.

I am saying that "half of the defendants" DID NOT carry out the justice sought by the ICC on the other half.

They did something else (an act of war) that should not be conflated with justice.

I agree. Having lived with a civil war and with non-western roots I find the Western attitude to things like this to be hopelessly naive. It is the product of a golden age following the collapse of communism and the subsequent unrealistic "end of history" optimism.

So in the case of Sri Lanka, was the LLRC set up and subsequently criticised as a mechanism to lend legitimacy to the way in which government forces conducted operations against LTTE? If so, would its mere existence not indicate some level of societal buy-in to the idea that actions should take part according to some judicial form of 'justice'?

The idea to enquire into whether actions were justified in the context of war. Very different from a criminal trial before actions are taken.

You're missing the point, "justice sought by the ICC" implies that the ICC just wanted to execute them, which is obviously not true.

The winning side destroying the losing has historically been the exception, not the rule. So why not?

Huh? You have that backwards. Since the dawn of human civilization, when two societies went to war the winner usually annihilated the loser: steal anything of value, smash the artifacts, execute the men, and take the women and children as slaves. Thousands of cultures were utterly erased this way. It's only recently that warfare has become a bit more "civilized".