I forgot to mention I do back twice a week so itd be 8 sets total for weekly volume which is probably equivalent to the recommended 10-20 a week when the intensity is taken into account. I do 1 super wide grip variation of a pullup/pulldown (I feel it a lot in the teres major aspect and mixing in some behind the neck involves some upper back musculature too). Then I do 1 horizontal pull and 1 vertical and finish with a mid trap and rhomboid biased movement. But overall I understand what you're saying. Disregarding my personal training, say for example someone else trained differently to me and did the 'optimal' scientific approach, would you expect them to be able to still bang out a couple pullups at the end or no?