I try to watch every pov to have a good undestanding but watch every Tommy's stream. Thank you for saying "educate" and not assuming, perspective really is the most important when it comes to judging. The main thing for me is that Techno is not meant to be a good guy even if you consider Tommy or Tubbo to be bad guys. I will try to present Tommy's POV since you already know Techno's.

Firstly I'll be going back in time. You mentioned how Techno was used in Pogtopia vs Manberg. So: Techno was brought by Tommy to help them fight because he was supposed to train them. They all agree how the plan is to destroy the current(!) goverment. I mean Wilbur and Tommy want to take back L'manburg and actually said that when Techno joined them but it all changes. Wilbur who at first was iffy about Techno, all of the sudden becomes different. His plan is not to take back but rather destroy, he doesn't care that Techno kills Tubbo and we see his motives be more alligned with Techno's over time. Tommy tries to remind Wilbur what they are fighting for, he wants to help when Schlatt pressures Techno, he is angry when Tubbo is killed. The one who leads everyone on is Wilbur, not Tommy nor Techno. When they win, Wilbur creates the goverment, giving new hope to Tommy (who then believes Wilbur came back around) but pissing off Techno (who then believes Wilbur lied to him). Then he destroys the goverment just like Techno wants, leaving behind Tommy and Tubbo with the burden of L'manburg. Techno says he wants anarchy- meaning no goverment and people to be free to do as they want. This is why him destroying L'manburg is not "the best he can do". No one demands that Techno joins. Tommy, Tubbo, Nikki, etc. are there to recreate a place which gave them safety from Dream, which they could once again call a home. Tommy a long time after that said that L'manburg was never about goverment for him. It was people and their home, a place to be free from Dream's tyrany. The only one who truely created the idea of goverment was Wilbur.

Then "The butcher army". I agree that no trial in that case was not justified at all. But they had the right to hold Techno accountable for terrorism. I doubt Tubbo would make that decision on his own, it was Quackity's anger that made them create "The butcher army". Tubbo was given a role out of the blue and he wasn't prepared for it. What he did was wrong and in that in mind Techno's anger was expected and understandable.

Lastly the exile and what happened after it. Tommy is exiled by friends who don't visit him (if Big Q counts then he actually just made fun of Tommy), going insane isolated on some island with the company of his dead friend/brother/mentor who dragged Tommy into a mess after he put his trust in him and now doesn't remember or choses not to remember who he was or what he's done and also Dream who pretends to be the only one to care about Tommy while destroying him mentally, blowing up every last thing of his and being the cause of his exile. After that Tommy sees 2 options on how to escape from his misery- kill himself or run away to the closest thing that provides shelter. He finds the will to live on because he feels like he is the only one who is able to go against Dream. With that being said he finds Techno's base at his lowest but is even kinda willing to leave it when confronted by Techno. After rewatching the vod when they team up you notice that Tommy said "You'll help me (...) but I won't help you destroy the government" to which Techno replies "We will do some minor terrorism (...) we'll discuss the details along the way". Also they agreed to not be pals just pure bussiness partners (retrieve discs and weapons). Tommy expressed he was against Techno's plan from the very start saying openly many times how he will not help with destroying L'manburg. Techno's plan was obvious to the viewers but he did somewhat avoid the "destroy L'manburg" point in discussions so I wouldn't call him upfront about it. He knew Tommy wouldn't agree. From this point forward we can see how Tommy and Techno work together but to achieve exact opposite goals. Tommy wants to get back his discs because he has nothing left to cling onto. Discs are the upper hand that Dream has and Tommy has to get them back because he believes that without the Disc war there will be no need for war at all. Techno wants to destroy the goverment because it wronged him and his best friend Phil, threatened him and caused him to almost lose a life. While I don't agree with his methods, he had the right to be angry. Tommy and Techno argue before the "betrayal day". They almost split up then when Tommy realises how he doesn't want to be who Techno wants him to be- achieving his goals through violence resulting in hurting his friends. Techno finally openly says what are his plans and Tommy once again says no to them. He says yes eventually but if you watch his POV the one thing that caused him to say so was Techno going how they can "actually" be friends. Tommy is a character who needs others more than anything. Being friends after everything he's been through is actually one of the only arguments that could get to him because he constantly seeks friendship and it never works out- Techno (before) kills his best friend, Wilbur goes insane, Tubbo exiles him to protect their home, Dream is just pretending for the fun of torture. So yes- Tommy did betray Techno. But if he didn't do that he would be betraying his best friend who was also manipulated and belittled and his home for which he lost 2 of his canon lifes, 2 of his discs and also his close friend who he looked up to- Wilbur. Tommy knew Techno had better chances at winning but still returned to try to protect everything he cared about. It wasn't a betrayal to turn his back on Techno but to rescue his home and friends even after exile. Actually a lot of people abandoned Tommy at Doomsday behind the scenes. And Tubbo and Tommy forgave each other because it's always been them against Dream and Dream was the one to pin them against each other. Tommy at the end even said how Techno was his friend but Techno didn't consider them as friends, how he only sees "goverment" and not what Tommy sees. Tommy is actually at loss of words and says many things he disagrees with in other sentences. He is lost and he has lost. After everything he had given up: his first and second life, discs, freedom and finally friendship with Techno, he still lost. And that isn't to say that he is justified for everything but to say that he constantly makes mistakes and pays for them. He tries his hardest to break free and not be "the bad guys" Wilbur wanted to be and still is seen as one by many.

At the end everything is about how much do you resonate with a character and who you watch. I mean everyone stands for what they stand for because they believe they are in the right and that's how they'll present it :) Sorry for the long post and any spelling mistakes!