Authenticate a user based on a token and not through mysql table - jwt

Question

round 2: trying to make this clearer:
I have two totally and completely separate services (both laravel 5.3).
One is an authentication service that has access to a user mysql database, permissions and role.
The other is a resource service. It couldn't care less about the user table and does not have access to any user table.
That means that any type of Auth::loginById()... would never work in this service because there is no user table.
I want to use JWT to have users access the resource service API, and have the user Auth to act as if a user is authenticated - but again - all I have are the claims inside the JWT - no user table. The claims include some information about the user - id, name, etc. I want to do something like this:
$userObj = JWTAuth::parseToken()->getPayload()->claims; // { id:4, name: Birdman, email: birdy414141#gmail.com}
Auth::login($userObj)
and then have access to the user object like usual
echo Auth::user()->name // Birdman
Has anyone tried anything like this?
I have found that doing this more or less works:
$u = new User();
$u->user_id = (JWTAuth::parseToken()->getPayload()->get('sub'));
$u->name = (JWTAuth::parseToken()->getPayload()->get('name'));
Obviously I can't $u->save() here because again - there is no user database.
I can do this though:
Auth::login($u);
and then I can later call Auth::user()->name properly...
I'm asking if I'm doing something exotic here or is this good stuff. Where will this fail?