I feel like 3H discourse gets fucked over a bit by people not taking into account that characters will say inaccurate information (without it having to be a plot hole). Perspective is a huge theme in Three Houses and characters are going to make, sometimes, dramatic actions based off that misinformation.
Like, Dmitri accuses Edelgard of being involved in the Tragedy of Duscur, but, she was like, 12 when that happened. It's a lot more likely that Edelgard was being experimented on or recovering from experimentation during that point in time considering that the Tragedy happens not long after Edelgard and Dmitri last see each other.
Likewise, Setheth accuses Edelgard of trying to become a false goddess when that's not even remotely close to her goals.
Edelgard makes a ton of false accusations and misconceptions about Rhea. She accuses Rhea of being a power hungry inhumane tyrant who has no regard for life outside her own when that just isn't remotely accurate.
And then there's Claude, literally the only major faction leader that cares to uncover the truth and nuances of everyone's decisions. He's literally the only faction leader to not act like his version of events is the definitive truth. He acknowledges that he and Edelgard are fighting for similar things: a system overhaul of Fodlan. He also doesn't oppose the Church because he's learned enough about it to want to keep it's institution in place. That's why he's the only faction leader that can survive in every route (I'd consider Seteth and Rhea to share the role as Church Leader since Seteth leads the Church Route but Rhea's the one actually in charge of the Church). Claude is also the only leader that doesn't make any false claims about other factions. I said a while ago that Claude would make the best ruler and this is why.
But going back to what I said earlier about discourse, this impacts discourse drastically because people can just pick whichever version of events they prefer and there's probably a character who claimed it went that way. The plot also doesn't seek to clarify events one way or the other in any route. So even if you've played every route, it's up to the player to make judgment calls on who's speaking out of their ass.
Between all the relevant character and plot details the game hides behind supports, endings, and other easily missable content and the fact that no two characters interpret the series of events that happen in the plot the same way (due to coming from various background, being present for some stuff but not others, having different priorities and biases that will cause them to interpret different things in different ways, etc.), no two players are likely going to interpret the events of 3 Houses the same either.
So, if you want to talk 3H, please acknowledge that none of the characters should be taken solely on their word, especially when describing major things. With the examples I gave earlier of misinformation in the game, it makes sense that Dmitri would place the blame of the Tragedy of Duscur almost entirely on Edelgard because he doesn't know about the Agarthans or Edelgard's history with them. It makes sense that Edelgard has a lot of misconceptions about the Church because once you start completely rewriting and erasing history (and the Church does openly censor literature, which is shown in Claude's route), any possible "true story" is more likely than the story you're giving. Alongside that, Edelgard is getting most of her information from the Agarthans and a very private source only accessible to the Imperial Family. It makes sense that Seteth might assume that Edelgard is trying to become a false god because he's been helping lead a religion based on lies for centuries. When you're trying to understand some part of Three Houses, you have to think about where that information came from, what factors might be biasing that information, and that there might be some detail that shines a new light on that information somewhere else in the game that you're missing. And that's generally a good philosophy to have when processing any information.
That's something I like about Three Houses. I like how you have to sort through a ton of biases and misinformation within the game to understand the story. If you let your own biases get away from you too much, you're going to miss the larger picture. The game let's you know exactly where everyone is coming from in some way and (almost) everyone is given a sympathetic eye in at least one route. And (almost) everyone is viewed as irredeemable in at least one route.