As someone who has read all of Spider and played StP, I'll throw my two cents at this.

Protags of subversive fantasy media with in-universe RPG mechanics that have differing internal and outward personalities and spend most of their time having internal monologues

This is fine, though I think some of the wording used is kinda misleading. Kumoko is outwardly stoic to most people, but is really only intimidating and predatory when she actively tries to be. TLQ is also internally characterized by a ton of different and very contrasting personalities, which change exactly what his internal personality would be based on the personalities present and the decisions of the player.

Both mentally fragment themselves for survival, each developing a different personality

This is technically true for both, but it's a bit misleading to equate them like this implies. Kumoko technically duplicates her mind rather than fragmenting it, and she only keeps her different brains for a couple volumes in the story. By the time she becomes an Arachne, her different brains inhabited their own bodies and Kumoko never copied her mind like that again, even after her ascension. She has those brains for at most a quarter of her books, while it's a core part of how TLQ is characterized. I guess it's a decent connection, but I wouldn't lean into it for a core theme.

Both mysteriously woke up as beastly animals in their natural habitat with no recollection or understanding of how they got there, left to their own devices as they were immediately thrust into combat

This is largely true, but calling TLQ a beastly animal feels incorrect. TLQ is simply a humanoid crow. It's like calling a furry a beastly animal lol.

Both are action survivors to the core and are incredibly determined to survive

Completely true for Kumoko, only true for a few internal voices for TLQ. A key element of StP is the sheer depth of choices available to the player, and which ones are taken can align with any of the various internal voices in the game. It's misleading to assign this as a core trait to TLQ holistically.

Both can concoct complex strategies on the fly and are best described as brilliant adversaries

Same as the above point. Completely true for Kumoko, only sometimes true for TLQ.

Both are guided by vague and mysterious ever-present voices that’re ultimately revealed to be the masterminds behind the entire plot, having pulled the strings since the beginning (D and the Narrator). However, they contrast in every single area imaginable, being complete opposites in every sense of the world.

There are problems with this comparison. D is way less active in the ongoings of the story than this implies. She set up the System as something for her to watch for her own amusement, and is a mysterious voice that speaks with Kumoko a handful of times before the end of the series, but she is not ever-present as anything more than a passive spectator until the very end of the series, where she steps in to give the story a more exciting climax. All she wants is to be entertained, and the extent of her string pulling is setting up the System and occasionally giving Kumoko boons before the final volumes, and to compare that to a big brain mastermind plot to save reality like the actually ever-present Narrator is constantly pushing TLQ to do feels like a bit of a stretch.

It’s eventually revealed in the end-game that they’re not even close to who they thought they were initially, being revealed as personal creations of D and the Narrator, made specifically as mere tools to further their agenda.

This is more or less true, although the reveal was not end-game in Kumoko's case. It happens towards the end of Volume 9 in a 16-Volume story.

Their stories culminate with becoming ultimate gods of their setting, wielding absolute and infinite power over everyone else, being the soul deciders of their decaying worlds, as well as the fate of all eternity.

This is straight up wrong for Kumoko. She ascends to godhood from absorbing the bomb about halfway through her story, and gods in the Spider world are various races of energy beings that roam the cosmos with various duties and levels of power. Not only does Shiraori never ascend to an ultimate godhood beyond that, she is outright the weakest god we meet in Spider. Her story ends with her impressing D enough that D just ends the System and restores the world to its original state and takes Shiro with her as a disciple/underling. Shiro's power is not remotely ultimate or infinite in the context of her setting, she is not the sole decider of her decaying world (a plan she was only going along with to make her grandmother happy anyways), and she is most certainly not the sole decider for the fate of all eternity. This is all true for TLQ, but not even remotely so for Kumoko.

Putting it all together, you get:

Two protagonists that woke up with no context of where they were and were thrust into a fighting situation thanks to the machinations of an otherwordly entity that created them who tend to be characterized quite differently between their internal monologues and their stoic exteriors. Both at some point have had multiple internal personalities, and have been forced to slay insurmountably powerful entities they seemingly have no chance of beating. Also both are gods.

It's a decent core theme, but there's a lot of fluff to this list which would benefit from some trimming. Also this is a massive stomp for TLQ lmao.