I'm not a fan of this example, no offense. It's not that you can do more reps with one exercise over the other.
I believe you what are missing from this picture is that most people only focus on these two motions as their primary upper body compound exercises. And the targets for these two muscles are the pecs (bench press) and lats (pull-up or downs). One of the secondary motion for these muscles is internal rotation.
Many people leave out the external rotator muscles, and this is what causes the imbalance and poor shoulder stability
No offense taken.You are absolutely right when it comes to imbalances between internal and external rotators. I was paraphrasing results of a study done describing the differences in strength from those 2 exercises exclusively.
Here's the abstract:
The Journal of Strength and Conditioning Research
Article: pp. 594–598 | Abstract
Volume 18, Issue 3 (August 2004)
An Analysis of the Ratio and Relationship Between Upper Body Pressing and Pulling Strength
Daniel G. Baker1, 2 and Robert U. Newton1
1. School of Biomedical and Sport Science, Edith Cowan University, Joondalup, Australia,
Baker, D.G., and R.U. Newton. An analysis of the ratio and relationship between upper body pressing and pulling strength. J. Strength Cond. Res. 18(3):594–598. 2004.—It has been posited that certain balances in strength should exist for opposing muscle groups (e.g., hamstrings and quadriceps) or actions (e.g., internal and external rotation of the shoulder) to improve sports performance or limit the likelihood of injury. Typically, expensive laboratory equipment such as isokinetic devices has been used to evaluate strength balances. The purpose of this study was to determine if two popular field tests of strength could be used to assess a concise strength balance in roughly opposing muscle actions for the shoulder girdle. The two opposing movement actions of pressing away from the shoulder girdle and pulling in towards the shoulder girdle were assessed via the 1 repetition maximum bench press (1RM BP) and 1 repetition maximum pull-up (1RM PU), respectively. Forty-two rugby league players, comprising 21 national league (NRL) and 21 state league (SRL) players, who regularly performed both exercises in their training, served as subjects in this investigation. The equivalence of the strength ratio (BP/PU × 100) and correlation between tests were also examined. The pooled data exhibited a strength ratio of 97.7% (9.0%) and correlation of r = 0.81 between the 1RM BP of 130.1 ± 20.2 kg and 1RM PU of 133.1 ± 17.1 kg. The small standard deviation exhibited tends to indicate that athletes should exhibit a concise ratio of around 100% if pressing and pulling strength have been addressed fairly equally in training. However, some athletes may have body types, preexisting injuries, or training histories that predispose them to either excelling or performing poorly during strength activities for either upper body pressing or pulling actions, with differences in strength of up to 15% existing in some individuals. These factors need to be taken into account when prescribing training based upon the strength ratio between pressing and pulling strength.