Taking care of someone, looking out for them, keeping them safe or protecting their interests is, for some people, a calling or vocation. You might call a person who does this a chaperone – if you are old-fashioned enough to know the term.
Being a shepherd has a lot in common but it’s different. Traditionally, the chaperone was present to supervise and protect a younger person at the start of their life’s journey. It’s a role that always ends in redundancy for the chaperone (chaperonic expendability?).
A shepherd also works to keep others safe, but it assumes the flock is helpless or permanently at risk, so they have to be much more restrictive and controlling.
Being a chaperone is a temporary position, a shepherd has a job for life.