I think no matter what the criteria is, there's always going to be some wiggle room just 'because' or because the rules are open-ended. I don't mind Skate Canada picking James/Radford
because they have the highest international scores this season- but if that's the most important criteria, it should be written as such. But their 6 criteria are very, very open to interpretation. If Worlds placement and Nationals placement don't count as much because they either A) are not a strong placement or B) the other skater/team wasn't in said events to compare, then make mention that those don't hold as much, if any, weight. They also needed to be clearer about what the 'other criteria' meant and how they determined if J/R were capable of finishing in the top two flights - is that based on their SP ranking in world standings, their best scores this year compared to Worlds last year, their overall ranking this season amongst all teams in the Olympics/Worlds? Who knows, and your guess is as good as the committee that decides things.
I think the USFS took a step in the right direction with what they did this year, because in 2018 I swear that the then-President tried to say the criteria was in place for potential medalists- we all know Rippon was not. I still believe that Malinin should've gone to the Olympics simply because both skaters were in the same tier, there wasn't a clear-cut reasoning of how they would be ranked in those tiers, and in the only head-to-head he had with Brown, he was not only a top 3 medalist, but also beat him by a decent margin.
But then I think about the Rudy Galindo situation. Super rare and may never happen again, but Rudy did not have the international results in 1996 nor did he have the Nationals result the season before (I think he was 8th). There was a prior rule in place about the National Champion getting a World/Olympic spot but I believe it hasn't existed for a while. What if the US only had 1 spot or even 2 spots? Send him? Of course, these days he'd have to get the TES minimums internationally anyways.
I like what Spain did this season, sending their teams to three direct competitions - two internationals and Nationals itself. The USFS couldn't have really done that with Brown and Malinin competing on different fall circuits, but I still think the JGPF being canceled hurt Malinin a lot.
And of course, for many fans it all depends on how well-liked said skaters are and/or if they have good personalities and good programs.
Regarding Nancy, I think she had a few things going in her favor. She won Piruetten on Olympic ice a few months earlier, ahead of Chouinard, Lu, Bonaly, Szewczenko, and Sato. Those were all top 10 names at the previous Worlds. I also think the fact that the USFS went with Ervin and Kwiatkowski in 1993 (and it backfiring, pretty much) made them want to pick a more reliable (even if unreliable

) skater. And mostly, of course they wanted Kerrigan on the team. The Olympic SP is one of the most-watched broadcasts of all-time on US television for a reason. The drama!