There's something to be said about repeatedly getting a large number of wins every age, I agree. But our OOP war this age was against a kingdom who claimed to have gone 5/5 last age. We crushed them in mintime, and they had an Avian core, which is pretty strong OOP because of the free elites. It's easy to go 5/5 in the 50-10 land/NW charts. There's a lot of targets available to pick from. Yes, there's a larger unknown so the chances of getting randomly waved are MUCH higher than in the top 5, but you can also be the one doing the waving to get wars.
I don't have experience with the LS of CoL, or Bravehearts, or Noobs. I'll give them the benefit of the doubt and say they're excellent war strategists, but the level of competition just isn't the same. I led Mythos through several wars, most of which we won, and I don't think I came up against any opponent that was as good as (for example) Hesus at war strategy. The guy's good, better than any leader I've warred against [I warred and beat Nesta once, but he ****ed up and gave me the button right after he explored so I don't count that. On even ground, he'd probably out play me]. Hesus got this good by playing with, losing to, and beating the best players in the game.
Top land/NW kingdoms are generally run by the best leaders in the game. It's hard to refine your leadership skills and strategies by warring the "above average" kingdoms, even if you go 10/10. You gotta beat the best to be the best!