AppleTV Hub?

Here is how to Set up your HomePod, Apple TV, or iPad as a home hub - Apple Support

Which generation of Apple TV?

I don’t immediately see a model that tops out at iOS 9.

Third-generation tops out at iOS 8, not iOS 9.

How to update your Apple TV - Apple Support

Identify your Apple TV model - Apple Support

Your iPad is too old. I think you need at least iOS 11. It works on iOS 12 but is limited on what it can do.. I have an old iPad on iOS 10.3.3 . It has a Home App but can only do lights. My other accessories don’t show up in it.

As to Apple TV , the article says this: To set up home automations, control your HomeKit accessories remotely, change user permissions, or stream HomeKit-enabled cameras remotely,1 you need a HomePod, an Apple TV 4K or Apple TV HD with the latest version of tvOS,2 or an iPad with the latest version of iOS.

Set up your HomePod, Apple TV, or iPad as a home hub - Apple Support

The newer the model with the latest OS’ , the better it will be to use as a Hub. Older models don’t do Automations well at all.