I just had a thought about the Poe/Holdo subplot in TLJ, which is this: Poe should have had Holdo’s objective, and Holdo should have had Poe’s.
Consider: Poe at the beginning of TLJ is painted as a brash, risk-taking daredevil who doesn’t flinch at throwing away ships and pilots if it allows him to destroy the enemy. As a foil to this, Holdo is painted as a commander who would rather run and regroup with her forces in order to live and fight another day.
And yet, when it comes to Poe’s mission, he decides on a course of action which would allow the Resistance to flee from the First Order in order to live another day, whereas Holdo’s course of action is predicated on sacrificing their one and only capital ship and regrouping on a fortress planet where they may be forced into making a final stand, and this is without the later plot development that requires Holdo to destroy their capital ship in a Hyperspace maneuver.
So as a little thought experiment, let’s just imagine a movie where Holdo has Poe’s mission and Poe has Holdo’s mission:
Holdo, as leader of the Resistance following Leia’s incapacitation, consults with her officers and crew and decides that the best course forward is to send a team to infiltrate the Supremacy and deactivate the Hyperspace tracker. To do this, she needs a codebreaker capable of bypassing the Supremacy’s shields, and so she herself volunteers to go to Canto Bight and find such a codebreaker (Perhaps she even knows such a hacker personally, since she has lived with such people in the New Republic for years). She orders radio blackout to protect against First Order interception, and leaves the Raddus with a handpicked few.
Poe mistrusts Holdo’s intentions, and believes that there may not even be a Hyperspace tracker. He suspects that Holdo is in fact a First Order spy, and her leading the mission to Canto Bight is her way of escaping a doomed ship. He speaks with Finn and Rose about an alternative plan if Holdo turns out to be a traitor, and together they discover that they may be able to evacuate the ship with cloaked escape vessels and ram the Raddus in to the Supremacy, destroying it.
Meanwhile, Holdo’s plan on Canto Bight is a success, and her team successfully infiltrates the Supremacy.
While this is happening, things on the Raddus have reached a breaking point. With no radio updates, Poe believes that Holdo has abandoned them and puts his plan into action. They load the crew into escape vessels and breaks the radio silence to tell Holdo that they are going to implement his plan.
On the Supremacy, Poe’s message is intercepted and because of this Holdo’s team is found and killed. Holdo is taken prisoner, and the First Order learns that the Raddus crew is being launched toward Crait, and they begin to light up the space around the Raddus with lasers, destroying some of the cloaked ships by chance. Poe, Finn, and Rose are the last ones on the Raddus when they realize that Holdo’s plan would have succeeded, and now they must rescue Holdo as well. Finn and Poe decide to go to the Supremacy on a rescue mission, and Rose stays behind to ram the ship into the Supremacy upon the completion of this mission.
However, Holdo tells Poe to escape and lead the Resistance in her absence, and detonates a hidden explosive on her person, killing herself and Captain Phasma in the process. Rose, in her grief, then makes the decision to sacrifice herself to destroy the Supremacy.
Finn and Poe, now escaping with the rest of the survivors to Crait, must weather this storm of their making, and lead a speeder mission to take out the big gun. Finn has decided to follow Rose’s lead and sacrifice himself to save the Resistance, but Poe wants Finn to survive, believing that someone will show up and allow them to be rescued, but Finn has lost all hope. Poe, however, has regained his faith because of Holdo and uses Holdo’s own words about living to fight another day. He rams Finn, and they both crash.
Anyway, all this to say that in this version, Poe makes clear mistakes and has an arc of recognizing his risky and destructive decisions and atoning for them through the foil of Holdo.