Man, thanks, that's pretty much all the information I requested and then some.
It seems from what you wrote that you have indeed done a lot of research into this.
I have a question though, and a couple comments, but first the question. Are you doing each one of those "sessions" once every week? Or are you rotating in even more variations?
The reason I ask is once again in regards to the topic of progression. If you are not performing the above workouts at least once per week, and progressively either using heavier weights or more reps with the same weight (and volume has a limit to which it is beneficial), this isn't going to produce the results that you're likely looking for.
My comments are in regards to statements like "you should change your exercises up every (insert cookie cutter number of weeks) so as to avoid adaptation." Which I know was not your words, but the words of several authors.
Hello? Aren't we lifting weights for the purpose of adaptation? Isn't hypertrophy a product of adaptation? This whole "muscle confusion" idea, while quite possibly born from good intentions, has gotten completely out of hand.
Let me ask you this; what's going to have a bigger effect on the size of your muscles? Adding 100 lbs to all of your major lifts, or using the same weight and doing it with a 100 different variations of exercise parameters (sets/reps/%1RM), sequence, form, and frequency?
The idea that doing exercises for more than "X" number of weeks will produce subpar results is ridiculous. Now, am I saying that you can do the same exercises for the entirety of your training career and still continue to gain? No.
But putting some arbitrary number on the time limit for using any specific exercise for a specific individual, without knowing that individual, their individual recovery abilities, strengths, weaknesses, lifestyle, etc... is crazy IMO.
Here is my suggestion, don't switch up exercises just because "X" number of weeks has passed. Switch them up when (and only when) one of the following occurs:
1) You get injured and can no longer continue with said exercise (overuse injuries fall into this category, and one of the reasons why I'm not that big a fan of high volume, but to each their own).
2) You stop being able to progress in terms of resistance (more weight or more reps with the same weight). And, if this does happen, make certain that you diet is in order. Don't switch out a perfectly good exercise just because your diet sucks.
3) You're certain that your diet and recovery methods are in order, but the exercise just doesn't give you the results you're after/you don't feel the exercise in the target muscle. This is a very individual thing and some people need to do specific exercise variations to adequately hit weak muscle groups.
That's pretty much it. Don't switch them for any other reason. The goals is to get as strong as you possibly can on every exercise that you do. Once you plateau (can no longer progress), switch to another exercise for the same muscle group (or even a different variation of the same exercise) and work on getting as strong on that one as possible.
Make sure you eat enough and rest enough and this should go a long way in helping you build muscle.