Honestly, they need to stop treating intelligence as a power level. It's better if they were to just show how everyone is good at their own field.
Reed is the best at coming up with solutions. Bring him a problem, he'll figure out the answer to it. If it was a puzzle solving competition, he'd win.
Tony is the best at advancing technology. You don't have to show him a problem, he's already busy working and iterating, always improving and moving science forward. If it was a challenge to find a flaw in a device and how to fix and improve upon it, he'd win.
Pym is chaotic. He doesn't have a direction or a method, he just lets himself be gripped by manic inspiration and let it take him wherever he wants, discovering things that no one had ever even considered before. If it was a science fair for adults, he'd win.
Doom is all about drive. He's brilliant, but science is just a tool to him, and he uses it to achieve his goals. That lack of devotion is his blindspot, but when it's properly aimed, he's unbeatable.
Cho is the quantum hypermind. He can process an infinite amount of data and find the solution within it. If you can define the parameters of the game, he's going to be the best in the world at it. Whether that's a game of chess, Go, or a game of capture the flag with robots, he's going to be the best at it because he can see every possibility. If the parameters aren't defined though, that's when he hits his limits.
Valeria is the prodigy. She is a child and isn't in charge of her own destiny, so her genius is instead tuned towards observation. She learns from the best geniuses in the universe and figures out how they tick, and because she's focused on them instead of something more abstract, she can predict what they'll think and outsmart them.
Luna is the powerhouse. She knows the least of any super genius because she's just so young, but she soaks up knowledge the fastest and she can brute force through problems on raw brainpower.