Chaos is from Dragonlance. Also, people would classify Ao as the DM too but even he has a master. Ao rebelled against LB so LB isn't omnipotent. And I believe LB can't control the denizens of the far realm since neither can Ao, so the ruler of the far realm could be greater than LB. I read on FR wiki that scholars speculated (aka its true) that LB is the world serpent. Ahriman, Jezirian, and many other greater gods are considered aspects of LB/ world serpent so it must be extremely powerful.
Don't believe everything you read on wikis
The concept of the Far Realm as a place/space/plane/reality is relatively new in D&D or should I say AD&D. I am pretty sure it wasn't a thing when Dragonlance started. And dragonlance has always been a little different with its deities (the only setting where Tiamat is a greater god). Regardless, D&D lore is so convoluted that it is really whatever you want. I mean technically LB hasn't been mentioned since 2e or 3e? Definitly not in 4e or 5e, it could not be a thing anymore. On the other hand, the World Serpent was a thing in 4e, and it definitely was not LB.
Then there is Gary's take on deities which is different.
And we also shouldn't forget that D&D handled things completely differently with no gods but "Immortals" that take the place of them.
So really, for 5e it is whatever you want as so little has been updated there isn't a "canon" answer for most of this. The only "official" thing is there are greater and lesser gods. Interesting, MOoT gives some more definition to what gods (I assume they are greater gods) can do) are capable of.
Personally, I only use canon when and were it benefits my ideas. I basically assume all D&D lore and mythology is only partially correct at best. It is the speculation of highly flawed "scholars" after all.*
*PS 4e was great about taking this approach, making all the lore nebulous and a particular point of view, not necessarily fact.
