You are sort of describing two different types of yards. The first one is a yard meant to operated like a real one where trains are made up and broken down. The second one is a "staging" yard which means a set of tracks usually double ended used to store trains between operating sessions. The staging yard also usually represents offline destinations not modeled on the visible or main part of the layout.
The track work for a working yard would be similar like you have shown. I might make some tweaks. The second scenario is what you describe for "parking trains" and hand switching.
You might want to think through which way you want to go with this before you finalize a track plan. Maybe think about how you plan to run the trains and what you want to do with them. If you just want to run different trains and watch them go, the staging yard is the best bet. If you want to interact more with routing cars to industrial sidings and switching them, you probably want a working yard but it can be done without it. And a staging yard is nice to have for operations too.
