You're missing MCP/Encom, King Candy, Monsters Inc, and Tomorrowland.
I do think putting Doris at tier 3 is underselling it. Doris does have its broken time machine and is successfully contesting Tomorrowland, which is arguably the most technologically advanced faction. Bill also probably deserves his own tier. Unlike the other tier 1s, he's either contained in the triangle, or he's out and nigh omnipotent.
Yeah, updated some of those, I'll do some more updates later. I put Doris as tier 3 because to me the cutoff for a Tier 2 position is "post-scarcity economy", but she's definitely fairly high on the Tier 3 scale and edging into Tier 2. Tomorrowland is a solid Tier 2 in that it doesn't need to worry about it's surroundings at all and can safely ignore everybody else unless poked.
Bill could possibly get a "Tier 0" for himself, but the thing with Bill is that, as long as he is contained, he
isn't that much of a threat to people outside of Oregon. While contained, Bill is technically a Tier 2, the difference is that he wants OUT, and is willing to affect things outside of his territor to make it happen. That's why he lands at Tier 1, if he was free he'd be "Threat Tier: Yes".
Hmm, have to disagree on Auto being in this tier. I'd put him in Tier 4 probably. The BnL wasteland is a large splotch on the map but most of it is just inert polluted wasteland. The single starship of the Axiom and its security forces are the only assets AUTO has. Their grasp on the wasteland outside of the Axiom's immediate environs is weak and they've go zero ability to project any power or influence beyond the wasteland's borders. Sure, they fit the 'more of an environmental threat' criteria of Tier 2, but beyond that AUTO is a weak king who'd crumple like cardboard if the Masquerade wasn't a concern.
Beyond that I largely agree with your tier list though.
The mark of the Tier 2 is that they're largely unwilling to project force outside of their territory, and they won't necessarily bother with tracking you down unless you poke them directly. Now as for AUTO's power level, I'm seriously unsure. I remember the female robot (what a strange thing to say) in the movie having a frigging plasma gun, so if AUTO has more of those, it's not harmless, but I'm sincerely unsure on the upper limits of it's power projection capabilities. Does the ship have some kind of BFG?
He may not be Gabriel Agreste, but he is Le Papillon, he don't need no pharmacist
Bill and Toffee may have similar goals, but don't really express the same level of power. Also this list is missing Tommorowland at tier 1, an existential threat to all of mankind cuz of that damn precog machine. Encom somewhere between tiers 1 and 2, and King candy between 3 and 4, with encom being the major player in cyberspace and candy being the evil resistance. and also Monsters Inc at tier 2, not world domination, but just background kidnapping.
ENCOM is firmly Tier 4 in Realspace. As for the MCP, it might climb to tier 2 in The Grid, but ultimately nobody
needs to go there. I'm not really great on TRON lore, can cyberspace represent any sort of threat to Realspace? If so, I might need to revise threat rating.
Monster Inc... I struggle with where to put them because they don't fit Tier 2. In fact, it's capabilities of military force projection from what we see in the movies are almost nil. I'm pretty sure Doof could conquer the place, if he were to find them. They might get a honorary Tier 3 because even if they struggle for energy production, they still have the land and people to throw at problems they want to make go away. Plus they have enough industry to supply an entire secret society, so they're not bad off. Yeah.
King Candy, I put him at Tier 4, same as ENCOM, which makes me feel bad because he's an absolute bottom-feeder even at Tier 4, while ENCOM stands at the very top of that category. Seriously, on the arena where King Candy could fight them, the MCP is actually, as
@Simon_Jester pointed out, pretty much Tier 2.
The tiering system gets wiggly around the edges.
Bill and Toffee aren't at the same level of power, but to a large extent that cancels out. Bill is very much an "all or nothing" threat; either he's pre-eminent and you're moments from dying or wishing you had, or he's not really a problem for you in that particular moment. Toffee operates on much more of a sliding scale, and at a lower absolute power setting, but on the other hand he is far less limited. He can seek out resources, allies, and enemies freely, and it is entirely conceivable that he could find out a way to blow up the world even faster than Bill could, given that Bill has to wiggle out of a straitjacket first.
Tomorrowland has a potentially world-wrecking thing, but is not overall a world-wrecking power, necessarily, in terms of the resources at their disposal. Imagine if Judge Doom had a magical idol that was causing global warming and would keep escalating forever until/unless the idol was destroyed. The idol would allow Judge Doom to in effect choose to destroy the world... but it wouldn't actually make him more powerful in a normal day-to-day sense.
Encom is pretty firmly Tier 2 in cyberspace; they're huge and pre-eminent but on some level appear to be satiated. The MCP almost certainly isn't plotting to destroy the place. On the other hand their realspace presence is pretty limited and strictly Tier 4 territory; Judge Doom could probably make them very unhappy if he put his mind to it, though the reverse is no doubt also true.
We can't pigeonhole everyone entirely, without a nuanced understanding of the strategic position of some of the specific Kings.
Yeah, while the Tier system can kind of divide things based on generalities, it misses a lot of things. There's people stuck in the space between Tiers, people that are absolutely underperforming in terms of how much of a threat they could actually be, and even the Tier 4's can punch above their weight-class inside their specialty. It's more of a... Rough division, but with a lot of rungs inside them to represent actual capability.
For example, even though Doof and Xanatos are in the same category, they're not exactly peers. Their statlines speak for themselves. Meanwhile, the Phantom Blot could probably steal Glomgold's fortune out from under him and climb to rank 3 in a lazy afternoon (realistically, more like a year), he just doesn't
want to.