Meh...changing routines to "shock" your muscles isn't a thing. The only thing your muscles know is the weight and the angle they're being worked. If you are consistently over loading (IE upping the weight), that's as effective as is gets. The only real "shock" to muscles comes from heavier weight or higher reps (drop sets to failure, etc). If you are training right in the first place, switching up your routine will do nothing other than break up the monotony. That being said, the difference between bro splits and full body for natty lifters is all about the bodies anabolic window (not referring to the "protein intake right after a workout bs). By hitting the same muscles every other day, you are keeping your body in a more anabolic state and promoting more muscle growth over hitting muscle groups once a week. Couple that with proper training (progressive overload) and you will gain more strength and size over a bro split. Now the bro split is definitely still useful, but at this point, personally, I would only use it sparingly to do touch up on lagging groups. Now if you're on gear, where your body is in a constant anabolic state, you can get stronger and bigger by sitting in your moms basement and eating Cheetos...but for a natty, frequency will do more for you than simple volume.