Godot's high level networking is so nice because it's easy to do either.
Since everything in Godot is nodes, you can assign "ownership" of nodes to peers. Every peer has full control over their nodes and then you sync the data via RPC.
That way, you can do authoritative by just giving all the ownerships to the server node, or p2p by sharing which nodes belong to who.
In the context of drawing though, yeah if you want people to mess with other people's strokes it becomes annoying.
