There’s no such thing as an optimal training split, an optimal exercise, or an optimal diet. There are splits that work the best for you though. Likewise, some exercises are better suited for you as an individual than others, and some diets that you can enjoy while others you hate. What’s best for you is not the best. It’s just the best for you. And that’s what optimization is: figuring out the best style of training, eating, and recovery for you as an individual.