If all you want is a nice big back, there's no need to do pull ups.

Your traps don't attach to your humerus at all. It attaches to your clavicle and scapula and mainly performs scapular movements.

Your lats insert on the humerus but to efficiently contract them to their origin at the base of your spine you need to work each side independently.

I got no issues with the lower back stuff, but honestly anything where you're holding weight in front of you and bending over will work the erector spinae.

By the way, the colour highlights are completely off.

This is what the erector spinae look like



They peek out at the bottom of your back but the whole muscle runs the length of your spine. It keeps your back from rounding and collapsing forward.

The part on the outer edges of the 'lower back' are your lats.



They originate at the base of your spine and run the length of either side of your back.

The rest of the exercises listed are ok, but far from ideal to train these muscles efficiently bro.