To give nothing away, it won't be exactly a friendly relationship. You might end up seeing all hell break loose.

If you'd like Advanced, you can take an infantryman in Patterson's (that is, that NATO soldier and his squad who share Tempest with the CTRG) "Vanguard" squad, or any other role that takes your fancy. Guerllia, CAS pilot, IFV commander, since there may be a wider sort of aspect to it in the future, and if you fancy seeing a different perspective in addition to the CTRG's, you can go ahead- just let me know what you got in mind.