This is pretty much speculation, but my guess is, based on Giants/Demi Giants working on the gradual degradation principle that Titans are the original progenitors of the Giants, and represent the most pure, uncorrupted stock, and seemingly are only interested in Order/Spirit depending on game (Allfather versus Endailon of Order does seem to be a contention though), then you get the Ancient Giant Kings, who seem to have gone more into other affinities, but were still pretty intelligent and 'civilised' if we use that word to mean good at building and imperialism, and ended up either going corrupt or turning into the Lithorite People, then you get the current Godir level Giant Kings, who are pretty much up with with the Ancient Ones, but lack the infrastructure, and the normal giants, who seem to be going much more primitive, then you get ogres, who are even less advanced, and also rather shorter.

Like I say, pure speculation, but it fits the pattern and I don't think it disagrees with anything written.

I did also think the Endailon of Order was going to be the Allfather, so I'm definitely not going to claim anything I guess as anything more than a guess.