Red Teaming has to be preemptive
Red Teaming has to happen constantly, it has to be part of the security planning of any organization. Think about it, one of the Rules of SOF: Competent Special Operations Forces cannot be created after emergencies occur.
Red Teaming is the same. If your security is compromised, it might be too late to run a good Red Team assessement or form an internal Red Team. Sure, you can from that point onwards, but why not include Red Teaming from the very beginning?
Having a good Red Team analyze also your plans, your procedures and your view of the future, will make your planning all the more robust. Having a Red Team view those plans as your competition or your enemy would, will help create a more solid solution.
Consider this when you go into your next iteration of planning.