They all have their own personality. I think the severums can handle a GT but fighting stresses severums out and weakens them so they might not last as long.
When they are young it is not an issue I worry about what happens when they are all 8+" Right now my chocolate is showing her mood stripes letting the new little guys know not to mess with her. Everything is fine right now she is not bothering them they are not bothering her.
I think adding small young fish to adults is the best way to make it work. What do you guys think?