I can’t convince you of it because you are buying what Nordas is selling. Jakob ran his PB when he was younger, slower (3:28.6 SB chasing Tim) and not at full sharpness (only 1 race, a 2k in buildup). He assuredly could improve it if he ran it deep into the season. The 800 often takes a few gos at it. Ditto Filip.
As for Narve, this “naturally born” load of drivel is self-invented. He could improve his first 100-150 by trying harder and working on it. For now, it is proudly not his tactic, and he’s a stubborn guy. But if he wants to run an optimal 800, he would be going out under 53 and he would fare fine.