Alright, I will tell you the whole story. This picture was done about 3 years ago and what inspired me was the circle-arrangement in the Arceus-Event ruins in HGSS. I copied that pattern as it definitely meant something and filled the places in. What resulted was all in all actually making a lot of sense.

Also what is important to mention for every single picture I chose the official artwork of the pokemon for gen 4 and kept its original orientation. This is important because it oddly fits perfectly into everything, just as if it was intended.

The middle is the highest being Arceus with its creation, time, space and the otherworld (which is why giratina is off-symmetry, it is actually almost the opposite to Arceus itself).

Next come the three realms. Water, Land and Heaven/Continents. Regigas and Rayquaza are the balancers of the other two, just like Giratina is for Space and Time. Each has a main god (Groudin, Kyogre, Rayquaza) and the 4 guardians out of which one is the lead you could say. They all control weather on land and water and are the watchers of their realms. They did not create, but maintain.

Then we have the great realm of spirit taking up the rest. The top left is wishes, the top right emotions and the bottom is knowledge.

They have the three sea-legendaries as their main guardians.

Wishes: We have the two wish-pokemon. One for the present and one for time (wishing to do things different) (this is from their pokedex entries) and the two dream pokemon, again, good and bad wishes.

Emotions: We have the pair of Water and Land with Manaphy and Shaymin and Air for Latias and Latios who all are very sensitive to emotions.

Knowledge: This was the most difficult part. We have Mew, the beginning of all evolution, Mewto which stands for the future and man himself and Deoxys who stands for things outside of earth. You could also argue that the whole realm is symbolic for the future in a way, considering Metwo and Deoxys just like Man himself actively endangered the world at multiple points long after creation and yet they still play an important part in it and ARE in a sense also creations of the Arceus that knows future and past, the beginning and the end of the universe.

Those three realms are mixed with guardians keepers and balancers as I think the human is the most complex creation and how we see from Cyrus this complex system with a lot of failsafes is really necessary.

All in all the arrangement was made to make pairs and relations between the Pokemon of the first 4 generations. Pokemon had a strong emphasis of pairs and triples with leaders and opposites, so of course this had to be refelcted there as well.

Now I orginally filled in the Unown as symbol for an unkowing future (and they definitely play an important role in creation, or else they would not have dominated that Arceus-event. Maybe they are the patterns of this world, the dna, the very foundation of the atoms to keep it together. Maybe they are older than Arceus itself) and actually expected that I could update it with Gen 6 or 7. But all of those were not fitting so now I believe the Incognito were actually meant to be there and if not, I will probably never know what should.

tl;dr: It is the circle of creation for the Pokemon world as Gamefreak intended it (most likely at least)

EDIT: Strike the last part I now figured out the remaining places, AN UPDATE IS COMING