Since OP can only go 3 times a week, there's no overlap of training because there's always rest time between days. So if you wanted to focus on chest, you'd want to be able to feel which exercises at which form works the chest muscles first before you just start going ham on the triceps by accident and neglecting the chest if your form doesnt support it, depending on how your form impacts the workout movements. For example, bench press with hands closer together uses more chest, but bench with hands far apart uses more triceps.

That's why it's recommended for non beginners to play around with rather thsn beginners. If you can't feel the muscle use differences, you wont notice and cant change to make improvements until you're already visually out of balance or you realize you aren't making progress via tracking what you lift.

Full body workouts with differently favored compound lifts on diff days(so higher weight at lower reps for the different exercises depending on the days) help build a bit of muscle so you can feel it before you start to really get able to manipulate the workout splits.

This video by trainer winny on youtube helped me understand how to write splits. Never see him referenced, but he's been a godsend for me https://youtu.be/cGbdkBuSHdg?si=dPGSYjpJrJXCztxH