I couldnt help but notice that the core workout is divided into three parts and all three parts are trained on separate days: the lower back, the abdominal, and obliques (side abs). Is that more effective than training all three muscle groups each training like in the workouts you posted on youtube? Same with shoulders and chest. Was just wondering why shoulders and chest are trained on different days as well. Is it more effective?
every time you workout your chest you'll also work your shoulders, every time you work your abs you'll also hit your lower back. In calisthenics you hit a lot of other muscle groups than the one youre actually focusing on, which is great because you'll gain a more completed and symmetric physique. It would be very hard to focus on both shoulders and chest in the same workout as they train a lot of the same muscles, so if you only do what seems to be chest exercises, youre actually also working on your shoulders :) And if you compare it with people doing split routines, often weight lifters, they maybe only train chest every monday, thats once a week. With this training method you'll already hit it a lot more, so nothing to worry about (y)
Hope that answered your q!