They should eat carnivore diets, they are carnivores. The pellet food you give them is probably 45% or more wheat or corn based, don't forget that. Look to see what the top 3 ingredients are.
It really depends on the fish...of the species you listed, I think blue acara and JD are heavily carnivorous, and sal and sajica are more omnivorous...
I wouldn't worry too much - like kdrun76 said, just pick a good pellet as staple and they should be fine.
The sajica is the only one that would really need some plant materials in it's diet, but a nice spurlina flake/pellet would handle their requirements just fine.