Yeah I´m not quite sure about that either. Boron still has his hordes of undead, which are annoying(even though I have ~15 demiliches) and Jeffr seems to always get back into the game with his f9/white centaurs. At least it´s always very costly to crush his armies.
And marignon must have a really huge blood income, not to mention that df marignon is probably the most powerful lategame nation, due to the goetic masters.
I have no idea what ygorl has, but he can´t have that many provinces.
I´m certainly number one in terms of power, with my gem income of ~150/turn, and I have the majority of the elemental royalty + the treelords. As for artifacts, I´m missing some of the really powerful ones, like the soulstone, the sword of augelmer and magebane, but I own pretty much the rest of the important ones.
So I guess I´m about as strong as Jeffr, boron and whollaborg combined, even though I don´t know what Whollaborg has
.