If you want high numbers of staff, look at some US Amtrak long distance trains. There's the loco driver ("Engineer"), the conductor, one or more brakemen, who in reality seem to be assistant ticket collectors, and just follow the conductor around. Then with the service crew there's a "porter" for each individual sleeping car, and some who manage the coaches as well. The diner has maybe 4 or 5 waiters, a steward in charge, two or three cooks in the kitchen, one or two snack bar attendants and a barman. I've also encountered travelling mechanical staff as well, looking after air con, plumbing, etc issues along the way. With all those jobs there's possibly one or two trainees as well - overall upwards of 25 on a train.