This was never shown on screen though and you have chosen to interpret it that way to fill in the gap. I have no confidence that Rian even thought about it in enough detail. He just wanted to go the opposite way from the OT. What if the Obi-wan / Yoda traditional mentor character on the hero's journey refused to train the hero... expectations subverted.
ROTJ Luke was so different to the old jedi order that this interpretation holds no weight for me. He was not beholden to the dogma of the jedi order because he was starting it all from scratch and he was working from his own experience. He didn't deal in the absolutes that PT Jedi believed in. He found a way to redeem his father where traditional jedi thought there was none. He embraced his emotions, love especially and attachment, using them as his strengths over the dark side whereas the PT jedi saw them only as weaknesses. He even used the dark side power, force choke. The ending of ROTJ went to such pains to show that Luke was so different which is why there was hope he would succeed where they failed.
With Finn that is not an arc, that's the same thing slightly tweaked. Run away bumbling idiot to a shift in his way of thinking until he stands up, says no more and puts himself in a position where he will likely not succeed to save others. Except in both cases he does survive. TLJ Finn should have been interesting, that dude had just raised a lightsabre against Kylo to save Rey, lost and had his spine severed. But he wakes up unscathed physically and emotionally (played for laughs when that injury and what he did should have been serious... expectation subverted tick). When Luke lost his hand doing the same thing he respects his enemy the next time and his own hubris for thinking he was ready and above completing his training. The lost hand is a key call back in Jedi leading to Luke growing and not making the same mistake as his father. Finn's injury is never mentioned again.
With Poe he never came off as overconfident in TFA, that was bravado because he knew he was screwed... (remember when Leia referred to Tarkin's foul stench and Vaders' leash, yeh same thing). Han on the other hand took the interrogation in ESB with no quips and one liners and screamed. Leia never obeyed anyone, she was always calling the shots, always sure of herself. I think Poe was more like her than Han in TFA. He already seemed like a capable resistance leader by the end of TFA so it was contrived to bring him down in TLJ to make him grow to that same position.
With Kylo I was only referencing TFA and TLJ (but yes the mask on off happens again in TROS because JJ was being petty). Arguably once the audience saw his face in TFA and the mask didn't go back on for the remainder of the movie, it never needed to go back on again in TLJ (it was there to play up the Vader illusion and for the reveal). In both movies he tries unsuccessfully to get Rey to turn and in both movies he then lashes out because she won't and then she bests him. Vader defeated Obi-wan in ANH (killing him), he defeated Luke in ESB (cutting off his hand) and finally was defeated in Jedi when Luke used the dark side. Kylo lost to Rey in TFA (yes he was injured), Kylo lost to Rey in TLJ because he was slower to recover from the force tug of war and Rey defeated more guards than him in the throne room. Kylo was humiliated by Luke in the TLJ not duel. Kylo finally defeated Rey in TROS and then she him with a cheap shot. Expectations subverted.
