The first air temperature listing is the actual air temperature (inside thermostat).
Air temperature 3 is external mounted sensor
Air temperature 4 (which I use) is floor sensor.
Why do they get these names? I have 10 of these thermostats, and they’re all the same.
It’s nice that I can utilize all values, but why are they all named air temperature?
They are the default names the integration provides. You can easily change them. Click on the entity, click on the cog icon at the top of the pop-up card. Change the name and entity_id to something more meaningful to you. Preferably before using them in automations or scripts.