If I may offer an opinion…feel free to disregard it, call me names, whatever.
I’ve taken my bodyweight from about 150 lbs. when I started lifting 9 years ago, to around 230-235 with a similar bodyfat percentage. Generally, I’ve used whole-body and upper-lower splits that focused on ocmpound lifts. The times I made the most progress were the times I ate the most calories, simple as that.
Not since the first 3-4 years (when I made the least progress) have I consistently used what I would call a ‘bodypart’ split. My concerns were strength for baseball initially (I played 2 years in college) and then training for competitive powerlifting. As a result of my training style, I gained a good deal of size but have a very ‘torso-oriented’ physique. This is ok with me, but would be unsatisfactory for a ‘bodybuilder.’
My opinion based on experience and observation is that focusing on the structure of the training week to this degree, to quote Dave Tate, “avoids the real issues of training.” Training needs to be progressive. It needs to be centered around productive movements. It needs to afford sufficient recovery and provide sufficiently frequent stimulus.
Most importantly, it needs to be supported by adequate nutritional and restorative modalities. It should be obvious to anyone with half a brain that this can all be accomplished by a variety of means. In addition to countless options regarding structure of the training week, there are countless options w/ regard to movement selection, sets, rep ranges, periodization schemes, etc…
What some people want is hard facts when it comes to training and there are none. There are lots of good ideas. Understand that if you dramatically increase your training weights over the next few years, while progressively gaining scale weight, you are going to be A LOT more muscular than you are now.
If you choose a variety of lifts that train the entire musculature, you will not have any big gaps in your physique. Which are the right lifts? Obviously this depends on the lifter. Some people are fine doing benches, chins, presses and rows w/ little or no arm work. Others need lots of direct arm work to get any growth there at all. It shouldn’t take too long to figure out which camp you fall into.
Regardless, physique, strength, and performance goals can and have been achieved with a variety of different styles. In contrast to the bodybuilders of the 70’s, there are the bodybuilders of the 50’s, many of whom were totally clean(and not nearly as educated nutritionally as bodybuilders of today).
These athletes used for the most part the Heavy, Light, Medium format and trained the whole body 3x/week. Tastes change over time, but the guiding principles of productive training really haven’t.
Get strong on the basic lifts, add whatever YOU need to adequately train your entire musculature, eat big, be patient, and don’t focus on insignificant shit and miss the forest for the trees.