Its not a bad thing to follow someone's methods but its not the best thing to follow someone else's pace or workout. If you do so, you will become second-rate in a third rate system. The very best body shapers & conditioned trainees molded their style all on their self mastery. Train in the exercises you're interested in and learn the technique; the rest is up to you. I like the way certain workouts are put together but like to put my own touches on them because I want to feel they're mine.
Mastering yourself takes discipline but it can be interesting. Learn systems that make you feel amazing and feel like you can accomplish anything. However; following someone else's pace to me most of the time is completely boring and unless you're in a team sport, its best to set your own pace, your own style and your own life. Following someone at their pace takes away a piece of yourself because you're a slave to their style. An extreme few of these systems let you have freedom to do what you want and live with real purpose.
Make use of what works and throw what doesn't in the trash. Its really not fun to be someone else because for one their lives are not always as glamorous as you think and plus even if you could keep up with them you can't look exactly the same as them so why bother trying to do the same speed and tempo on a video that for all you know is just a marketing scheme to program you into their little foundlings. Be your true self and master your own body inside and out.