control multiple devices remotely and simultaneously

[Goldentongs]

Not sure if this is the right place to post, but I assume devs will probably know if this is possible at all or if already available, before I start thanks in advance to any who reply with help.

I want to be able to connect and control multiple android devices remotely via the Internet, sending the same command to each device simultaneously.

I do not need many functions, although some extra features would really help but will get to that later,
I need to be able to upload new media content to each device and then display that media content on each device, that is it. (am open on how to display media, whether slide show or single video does not matter, sound not needed/optional)

All devices will be identical and will not be used for anything else.

It would also be nice if I could remotely check if devices are switched on and running normally.

I do know I can get remote access apps, but this would mean connecting to each device one by one which is not an option, as eventually looking to control about 200+ devices.

Someone please let me know if this is possible, whether it's already possible or whether it can be developed.

Thanks in advance to those who reply with anything helpful