Luthen and Saw alienated all their allies through unnecessary 'necessary evils' and ended up getting themselves killed because they were convinced that their way was the only way that would work.
The rebellion is a much larger operation with political, military, and intelligence branches, while Luthen and Kleyla is just espionage and black-ops, so they likely end up missing the forest for the trees.
But we know from Rogue One that the rebellion is not shy about following Luthen's playbook. Draven ordering Cassian to kill Galen Erso is a prime example. Or Cassian's "we have all done horrible things for the rebellion" speech to Jyn before the mission to Scarif.
And in Andor we are shown how Luthen's methods are necessary. Mon Mothma would have been captured if left to Bail Organa's plan, Lonni would have been burned and never have the chance to uncover the Death Star project if Anton Kreeger had been warned the empire knew of the raid.
So in the end, the Luthen - rebellion rift felt a bit artificial, or at least driven as much by the big egos of the people involved rather than by strong ideological disagreement on methods.
Meanwhile Luthen's paranoia resulted in him murdering people who could have helped the Rebellion with the resulting trail of bodies leading the Empire to his door.
He decided Andor was a liability and rather than even attempt to sway him to his side his first move was to murder him. Every time he was finished with a source of information or funding he murdered them.
Cassian definitely was a liability. He made it clear several times he was in only for the money so he could disappear after having killed the two security officers on Morlana, and didn't want to join the rebellion. And he actually did that, leaving with his cut after the heist.
IMO, Luthen did not think Cassian could be a traitor (we have seen Rogue One so we know he isn't), but the risk of him being captured and forced to reveal what he knew was too great. The empire knew who Cassian was and he was not willing to leave his family behind to disappear cleanly. He changed his mind and decided to join Luthen only after the empire came directly after his family and friends. And the reason he broke with Luthen in the end was about Bix.
Ty was blackmailing Mon Mothma. At the very least, his behavior at the wedding showed he was too emotionally unstable to be trusted to keep his mouth shut.
About half of Luthen's plotlines in Andor were him trying to deal with the consquences of his last attempt to avoid dealing with the consquences.
I only can see the bug into Scunden's art piece fitting into this definition. We didn't see any actual fallout from things like Ty murder.
What we see is that Luthen gets more and more isolated, but again we are also shown he is actually effective and the rebellion has no qualms following methods when they believe it necessary, so to me it falls somewhat flat.