I think what he should say is that a growth kingdom that doesn't war much will have a though time crowning.
Yes, a warring kingdom that happens to grow a lot by warring will not be at the usual disadvantage when they fight a growth kingdom because there's no more cows. However, a warring kingdom like Bravehearts or NOOBS aren't dumping their pool, and so they won't be warring any kingdoms in the top 5 Land/NW charts. That puts them at a disadvantage to get WW crown. If I were a betting man, I'd put gc on Divinity or Barcoloco winning WW crown, already in their 4th war against a top5 land/nw kingdom. If they war 2 more times (which both kingdoms like warring, so that's possible) and win every war, they'll be in a good position!