I've only ever done #1.

Not too keen on dying or injuring myself... XD

I feel like for #3 and #4, it's either their 1st day on the job or they've been doing it for 30+ years, no in-between.

What all of these diagrams are missing is someone to hold onto the ladder on the ground while the other is working.

I was a part-time worker on a construction site when I was 20yo. Have seen all of these, have done #1, #2 and #3 myself. There is another variant that's missing: "this ladder is too short, let's duct tape two of them together!" (don't do that, seriously, this is probably the most unsafe option).