Reading through some of the topics posted, and after listening to the latest podcast (245), I have developed an idea I think could be a solution to our collective woes.
Part 1: The Islanders Themselves
For this segment, I take some inspiration from H.G. Wells' The Time Machine. For those who do not know, in this work of fiction, in the distant future, humans have evolved into two separate subspecies. There are the Eloi, the simple, childish, weak, yet prosperous surface dwellers, and there are the Morlocks, the strong, organized, carnivorous beings who dwell underneath the surface of the world.
In my idea, the two subspecies are not quite as separate from one another, but rather separated for slight characteristic differences and perhaps politics. The two subspecies of islander would be Matoran, the smaller, weaker, but still skilled group, and the larger, stronger, more gruff Glatorian (I like this name from G1).
The unique trait/power of the Matoran would be their limited access to elemental abilities, and Matoran villains would likely try to use the elemental power as their main tool for evildoing. This is not to say, however, that there would not be Matoran who are highly skilled with weapons or in hand-to-hand combat in general.
The unique trait/power of the Glatorian would be the fact that they have no access to elemental abilities, but they are more physically powerful.
The two would be more like dissident factions than two whole subspecies, but they are definitely distinct. So, in any given region of Artakha, there would be a Matoran population and a Glatorian population, and the groups could have different relationships with one another depending on the region, and they would have different cultures, increasing the potential for world-building.
Part 2: Differing Cultures
Now that we have established the two groups, we can get into the basic cultural ideas/behaviors of the groups.
To start with the Glatorian, I think it would be interesting to have the 'warrior-class' kind of people worked into and integrated into the cultures of the regions. For instance, there would be some Glatorian who serve as guards/warriors in the main Matoran settlement in the Region of Sand/Stone, and there would be some Matoran who also do this. But because of their physiology and inherent traits, the Matoran would use their limited elemental powers in combat more heavily than weaponry, and the Glatorian would simply have greater ability in battle due to their increased size and strength, but less elemental resistance due to their lack of elemental power. In addition to the cooperative Glatorian who live and work with the Matoran, there could be factions of Glatorian who do not value the elements and/or the Toa at all. Due to the fact that they have no elemental power, Glatorian could never become Toa, and from here stems their spite.
These Glatorian who separate themselves could be hermetic and peaceful, or they could be violent raiders who pillage the land with no regard for anyone but themselves. Raider bands could form and thus pose a threat in the world that is more advanced than wild and dangerous animals. Additionally, there could be groups of Glatorian separate only geographically from the cities. I imagine a Glatorian order of knights who live in a frozen tower on a precipice over the City of Ice, who have taken up the duty of protecting the city in the absence of the Toa.
The Matoran could also have rogue groups, such as a band of elemental warriors who use their powers to enhance their pillaging abilities.
Part 3: The 'Sets'
Perhaps the most divisive issue facing us in the fandom today is the conflict between Hobbit legs and normal legs.
My ideas are not perfect (no idea is), but I believe that having two physically different types of 'citizen' can help with this. Because there is now a split in the population of islanders, there is a feasible reason for why one non-Toa could be physically able (taller, stronger) to dominate in weapons-based combat, and why another non-Toa could be able to manipulate combat through elemental means, and perhaps not be physically imposing (shorter, weaker).
In other words, the Matoran would have Hobbit legs and elemental ability, and the Glatorian would have standard legs but no elemental ability. Both are skilled in combat and intelligent. Both have interesting cultures which are not inherently better than one another. One group is not better than the other, or more special than the other. This also makes the Toa even more special. They have the ability to unite the islanders against evil, and they embody the mixture of the physical traits of both groups combined: the strength of a Glatorian and the elemental aptitude of a Matoran.
Hopefully, my idea is interesting, or at least mentally stimulating. Let me know your feedback!
Thanks for reading,
1st Humor Platoon, Pun Division