All very good exercises for building back.
The problem with things like pullups for back is that when most people fail the lift, there back is not what fails. Their shoulders or biceps fail, even with an overhand grip. Your back has many more reps to give. I call it a good upper body exercise, but horrible back exercise.
Well brother, what do you recommend. My back is the only thing that grows on me. It is also the body part I train the least yet is the most defined and got a good spread.