This bestiary is not sufficient to run the Kingmaker Second Edition adventure path in Pathfinder 1st Edition. It gives absolutely no guidance on treasure conversion (including custom magic items from the AP not being converted at all). It doesn't give any ideas on even roughly how to convert skill checks and DCs. Even the enemy stat blocks have a disclaimer of (paraphrasing) "we just winged it, see if it works for you".
And that fails quickly. The boss of the new chapter 1, for instance, is, by the book, a TPK. It's a party of 1st level adventurers, at the end of a dungeon sequence (i.e., down in resources) facing off against not just a 4th level fighter, but a well-optimized one with tuned gear. (+10 attack, 1d12+8 damage is unacceptable to put against a party of 1st level characters. And even worse when that foe has AC 18, _and_ good-for-level saves). And this fighter has friends, too!
Expect to need the 1e adventure path available and even then make constant adjustments (because the revised AP changes the level pacing and has new content).
This, sadly, was a very poor showing from Paizo.
As an added note, this is effectively the same price as the 5E version of the same book, while being about 50 pages shorter (for their own system!) The print edition does have a small price difference for this.
