Photon UE4 which architecture


I am on a game project, with multiplayer purpose, and persistent world (?).
to host such a server, I take a look, at photon, which free for tiny purpose (and it is my case).
But I was wondering about game architecture when using something like photon, which seems to be an heavy broadcaster.

For FPS purpose, it is quite simple, each player maintains its own physics, and broadcast personal information to other player.
For more complex game, with IAs for example, I was wondering who manage IA behaviour? it is client? Maybe with repartition over connected player, in the aim, that each player has a part of IA to calculate.

I think, using photon, you can’t maintain an authorative server with all objects, physics, and so on… but give to each client to be authorative on its own objects.