Very nice explanation. Thanks motomike!
In practice, both the Slim and the Fat Boy can close and adjust, and the resulting aggressiveness and angle will be 'somehow' usable, but that's unpolite on the razor, forcing the mechanism.
Razor: Fatboy, Slimboy, Tech, Knack.
Brush: Kent H8, BK4, Omega boar (small, big).
Soap: Woolfat, C&E Nomad, Proraso Green, Tabac, Cella.
Cream: Valobra Mentolo, TOBS Sandalwood.
Aftershave: Floyd Blue, Proraso Pre-Post, Dopobarba, Crema.
Other AS: Chimique Clinique, Capucci, Cerruti 1881.
All items top to bottom in my taste- YMMV