Why would an ace be shook? If he's the best pilot in the resistance that means he has combat experience and survived countless battles.
Han? Are you new to Star Wars? He's been a smuggler, dealt with cutthroat criminals, been in countless battles, caught bodies, fought the Empire, etc.
Finn had 1 real combat mission. Rey didn't cross the First Order he did. When he saved Poe his plan was to get far away where they couldn't find him. Poe took him back to Jakku which means they'd be after him in a minute. Why the hell would he not be scared? He's alone vs an army with a physco jedi. He was grabbing her hand to pull her outta there and she didn't understand the danger they were in. shyt didn't get real for her until she tried to open the box and got scared of the visions.
Context...
Why couldn't both Poe and Finn be aces and the best in their respective fields (Pilot and Soldier) from the jump?
Why couldn't Finn have been an elite and highly competent stormtrooper who has a name like "Phasma" who decides to say "fukk it, I'm done" and gets hunted by his former handlers on some Jason Bourne shyt before meeting up with the heroes, changing his path and becoming one?
This is how you described Poe, a new character: "the best pilot in the resistance that means he has combat experience and survived countless battles" , "the best pilot in the resistance" and you're still not seeing the contrast and mess-up with the Finn character?