What is the point I'm missing? You think Alex Yee is going to step up to 70.3 and IRONMAN racing and immediately dominate Hayden Wilde, Jelle Geens, Casper Stornes, and Kristian Blummenfelt because he's a 2:06 marathoner?
The three Norwegians you mention have every bit the W/kg of any in the sport. Do I think guys like Magnus Ditlev, Sam Long, and Trevor Foley stand a much better chance at Kona than Nice? Absolutely.
But the reality is these Norwegians aren't that small and aren't that big, so they can dominate on both types of courses with lab tested VO2 max figures in the 90s. Alex Yee is tiny. I would not be surprised if he could manage a meager 275 watts for an Ironman bike leg and follow that up with a 2:25 in the heat, which would have been more than enough the year Jan Frodeno rode 262W for the win. But it's a different game now and I wouldn't be surprised if 275 watts and a 2:25 doesn't crack the top 5 in Kona. Can he do 330 watts for an hour to stay attached before the climb to Hawi? Probably not.
Lange is a relatively lousy cyclist, and now that the top runners in triathlon are posting power not that much lower than Ditlev and Laidlow, they're never really going to be threatened by those guys.
I'm not sure why Pearson is an irrelevant comparison. He's faster over a half marathon than Yee. He's getting crushed in T100 because he's putting out 325 watts for two hours while being on the bigger side, while guys like Rico Bogen push 375 and smaller guys like Geens push the same power.