RAG Services vs. In-House Recruiting

We're having an internal discussion about the best way to handle recruitment for senior-level positions. Some are advocating for using external RAG Services to tap into a wider network of passive candidates, while others believe we should keep it all in-house to maintain control. I see the pros and cons of both. For those who use a hybrid model, how do you decide which roles you outsource to a resource advisory group and which you handle internally?