Having a completely separate org that specializes in one role, but is associated with TEST (either via alliance, or word of mouth) is going to prove less effective than having a sub-group within the main TEST org.
If the org controls are at least on par with EVE Online then it should not be an issue to create a group that focuses on one thing, but doesn't require members to join a different org.
Once we start getting some real concrete info on how orgs will work in the PU we'll be better equipped to handle role delegation/management.