When I do my 3 day routine I like to switch it up alil different then what's traditional but that's cus my arms can take a crazy amount of abuse and heal fast. This way I'd cheat in a double arm workout every week since chest and back works alot of bis/tris on their own. That and I loved be able to lift much heavier because my bis/tris wouldn't be as fatigued from my chest or back lifts. I'd would also sometimes superset. For example curls sets in between bench sets. Or skull crushers in between rows. I don't superset with deads and knock those out first because I don't like my arms being fatigued lifting that much weight. Scared to tear something.
I prefer a 5 day but I love this as an option if I have a busy week or just wanna switch up to more cardio on odd days and mix it up