In Cube (1997), it's strongly implied that the participants in the Cube were chosen for a specific reason:
Quentin McNeil is a competent but disturbed police officer who cracks under the pressure of the exercise.
Joan Leaven is a mathematician who takes the first step to "solving" the Cube.
David Worth designed a chunk of the Cube.
Kazan is an autistic who has the ability to factor the primes necessary to solve the Cube.
Dr. Helen Holloway is a doctor and conspiracy theorist.
Rennes is a famous escape artist.
It's possible to debate Holloway or McNeil, but the other members have such unique background and talents that it's very likely they were specifically chosen as part of whatever grand design (if any) controls the Cube.
The first victim, credited as Alderson, dies before he meets anybody and doesn't live long enough to reveal his background. I'm curious if there was some intended uniqueness to him as well that didn't get revealed because of the brevity of his screentime.