I tried to do showcases with super AI enabled and it was unplayable, either with friendly skill set to 1.0 and enemy skill 0.
I don't know exactly what is this option?
But whit it enemies are too awareness and got superhuman's skill, and it like it doesn't affect friendly one. To finish mission you're always alone, friendly forces finish always done.
I tried with difficulty set to elite and it was really much better, more realistic.