Beginners giving advice to beginners? Fancy that.
TBT increasing “neural efficiency” better than splits is a complete load of bullshit. So is the concept that simply squatting more often will magically make you gain more weight and muscle…
If you are capable of training normally, there is no reason for you to “stick out” absolute novice training.
The 4 day split you and your friend came up with, and even the exercises in it, is perfect for right now. Commit to it.
And as far as your goals and how muscle mass is actually built, you seem a little confused:
Reading many of the articles on this website can give a lot of people the impression that training for “hypertrophy” and training for “strength” are two completely different, and opposing things. This couldn’t be further from the truth.
Muscle mass is built by lifting progressively heavier weights, repped to failure (usually in the 6-10 rep range), and eating enough protein and calories to gain bodyweight.
The “X Factor” is how much willpower and intensity you put into your workouts, and you won’t make progress without it.
To illustrate what I mean, if you can bench 95lbs x 5 now, and in 6 months you bust your ass in the gym and gain 15lbs of bodyweight, and then you can bench 195lbs x 5, this will correlate to an increase in pec size.
Here are a couple of links that should clarify any misconceptions about training to gain muscle mass: