CT, studies show and you have written how training a muscle group directly multiple times a week is better than 1x a week.
In you experience is there much of a difference hitting say chest 1x a week 12 sets vs 2x a week 6 sets? Mike Israetel also writes how multiple times a week is better but, that at the end of the day you still get 85-95% of the same effect.
You can get results with any approach if you are training hard and are motivated. Iāve worked with bodybuilders who absolutely wanted to train each muscle once a week because they liked to focus on only once thing and maximize the pump for that muscle. And even though itās not optimal āon paperā if it motivates them more than doing a smaller volume 2-3 times a week then they will likely get more results.
If there is one thing that Iāve learned developing the neurotyping system is that the most effective program/training approach is the one that motivates you the most. Even if it is not perfect in theory.