The arc I've been planning for I15 involves several custom groups made out of standard characters. The feature I was waiting for was the auto exemp feature for standard groups. Basically I wanted standard enemies that you previously couldn't have together in a mission.
One of these groups was a Vanguard Powersuit group where Vanguard has different powersuits on loan. this group consisted of:
Crab Spider Slicer - 30-54
Crey Voltaic Tank - 46-54
PPD Shell - 36-40
Vanguard Soldier - 35-54
Scorpinoid trooper - 40-54
The arc is meant for levels 25-35 so i set the parameters accordingly
In the mission there were only level 35 Spiders and Vanguard soldiers(the ones within level range)
To test the problem some more I made a test custom group. This group at first had Axis Americans (40-54), Bobcat Followers (45-54), and Black Swan Shadows(45-54). I set the parameted for 25-35 and went in and found a nice mix of all 3 groups all level 35. I exited and added Nemesis to this custom group(30-54). I went in and it was all Nemesis.
So adding any standard character that is within set parameters seems to negate the auto-exemp that would have occured otherwise.
I certainly hope this is a bug and that I will one day be able to see my epic Vanguard Powersuits vs Rogue-Bots battle!!!

Have a nice day
----> the guy who reads but never posts