Show me the law firm or doctor's office that has 3,000 lawyers/doctors and I'll listen to your down with seniority argument.
In the US:
1 - Baker and McKenzie Chicago 3,779
2 - DLA Piper Chicago 3,452
3 - Jones Day Washington 2,517
4 - Hogan Lovells Washington 2,344
5 - Latham and Watkins New York 2,008
The NHS employs 109,000 doctors.