Explanation of two typical ranges of humanoid height, ~2m and ~1m?

Question

In the films, we see mostly typical human sized sentient aliens (Rodians, Gungans, Gamorreans, etc) at around 2 meters tall and a minority but still sizeable number of sentient aliens that are more in the range of human little people (Ewoks, Jawas, Ugnaughts, etc) at 1 meters tall. There aren't many in between (maybe Maz Kanata at 1.5 meters), and there aren't many smaller (Yoda is slightly below the 1m at 0.66m, Salacious B. Crumb at 0.7m) or larger (Chewbacca is just 2.28m, Kaminoans are a bit taller). There are some major deviations like Jabba the Hutt, and even some giants outside the films. But most of the aliens we see are in one of two ranges, either ~2m or ~1m.

Out of universe this is obviously because of the actors we have to work with here on Earth. Although it is interesting that Yoda and Salacious are still not far outside that 1m range even though they are puppets rather than people in suits, and so could have been even smaller. I suppose it comes down to making relatable characters...

But in-universe is there any explanation of these two size bands being most prevalent in the galaxy?

Answer 1

Yes. Sort of....

In-universe, Wookieepedia cites this as a result of the humanoid species being the most common type of species in the galaxy.

Since Humans were the most common sentient species, they were often considered to be a standard or average to which the biology, psychology, and culture of other species were compared.

Naturally, it seems reasonable that most humanoids would then share similar characteristics with humans (i.e. height and width).

Generally, it entailed having a basic anatomy or construction similar to Humans, that is, a central torso with a head on top, two arms symmetrically arranged on either side, and two legs symmetrically arranged below, providing an upright bipedal stance.

Of course, it should be noted that not all of the species in the Star Wars universe are humanoid and that we, as the viewers, are exposed mainly to humans and humanoid species for fairly obvious reasons.