This response is based on the information provided.  We suggest you discuss with your contracting team, program manager and/or legal department as appropriate. 

The FAR/DFARS does not have specific guidance regarding teaming arrangements and does allow teaming.  The concern for your team is the effect on legitimate competition.  If your team has made the decision this acquisition is sole source, then you must have already assessed the marketplace.  If this situation is justified as "Only One Responsible Source...", it does not preclude the prime from entering contractual relationships with subcontractors and vendors to accomplish the task.  Many large businesses form teaming arrangements for work in which they complement each other.

If you believe the particular business arrangement is intended to subvert competition you need to raise the issue with legal and the Naval Criminal Investigative Service.  You will want to have some offer of proof of illegal intent.