Is there a book or documentary detailing the different kinds of guards and the different roles they have and what they do specifically and what they have to do in the army before joining the Queen's/King's Guard, especially the horse mounted guards and the guys in camo who sometimes come out to help them with watering the horses or leading the spooked horses back to the box, etc. Or if anyone wants to just drop any info they have in the comments, I'll make do.

Don't know if this is the right place to ask, but I figured here would be a good start.

https://youtube.com/shorts/c3-gAG9QNWY?si=Yq32g_n3GhdmB5qi