The CW's Crisis on Earth X is a fine example of a superhero team-up. However, Crisis on Earth X (all the CW show's crossing over) did showcase how useless people with no powers really are in a physical confrontation with people who can fly, move, faster than sound, freeze objects at a distance, turn to steel, and the list goes on and on. It was hilarious when Flash and Supergirl arrived and then had to wait for Oliver Queen (Arrow) to show up on his motorcycle. As he got off he said, "A reminder: Superspeed...I don't have it."
I've come to this conclusion: live action realization of non-powered heroes next to powered ones strains suspension of disbelief to uncomfortable levels. Oliver (Arrow) is no more help at holding up a building than the Batman is trying to fight non-human foes. Black Canary had to forget she had a superpowered cry so a Nazi Arrow could beat Team Arrow. Additionally, there should never be a situation in which Sara Lance (White Canary) could ever be in a fist fight with Supergirl for this reason: Supergirl punches her dead and moves on.
Marvel does it so much better when it comes to this kind of thing except when it comes to Black Widow and Hawkeye. Tony Stark has incredible technology (as does Falcon) which kind of gives them an edge. But Black Widow and Hawkeye should just be dead.
Don't get me wrong. I love these characters. I'm just really aware that I need to "suspend disbelief" when the non-powered superheroes are on screen. They need "plot armor" really bad, and I need to enjoy fiction for what it is.
I also loved Crisis on Earth X. Here are highlights:
1) Iris and Felicity kicked some Nazi asses.
2) The wedding fight was amazing.
3) Seeing Kara sing at the wedding was incredible. She has such a wonderful voice.
4) The story definitely passed the Bechdel test.
5) The death of Stein. This was devastating not just to the Legends and his family, but to all of Team Flash because they've been building toward this end for years with shared history and crossovers. His death was a perfect example of why Crisis on Earth X worked so well.