Add more explicit docs of top level coexistence (#29921)

akka-docs/src/main/paradox/typed/coexisting.md

@@ -88,7 +88,17 @@ Java
 
 @scala[That adds some implicit extension methods that are added to classic and typed `ActorSystem`, `ActorContext` and `ActorRef` in both directions.]
 @java[To convert between typed and classic `ActorSystem`, `ActorContext` and `ActorRef` in both directions there are adapter methods in `akka.actor.typed.javadsl.Adapter`.]
-Note the inline comments in the example above.
+Note the inline comments in the example above. 
+
+This method of using a top level classic actor is the suggested path for this type of co-existence. However, if you prefer to start with a typed top level actor then you can use the @scala[implicit `spawn` -method]@java[`Adapter.spawn`] directly from the typed system:
+
+Scala
+:  @@snip [TypedWatchingClassicSpec.scala](/akka-actor-typed-tests/src/test/scala/docs/akka/typed/coexistence/TypedWatchingClassicSpec.scala) { #create }
+
+Java
+:  @@snip [TypedWatchingClassicTest.java](/akka-actor-typed-tests/src/test/java/jdocs/akka/typed/coexistence/TypedWatchingClassicTest.java) { #create }
+
+The above classic-typed difference is further elaborated in @ref:[the `ActorSystem` section](./from-classic.md#actorsystem) of "Learning Akka Typed from Classic". 
 
 ## Typed to classic
 
@@ -145,4 +155,3 @@ the child, for example if a classic actor creates a typed child, its default sup
 actor creates a classic child, its default supervision will be to restart.
 
 
-

akka-docs/src/main/paradox/typed/from-classic.md

@@ -159,7 +159,10 @@ typically performed from the "outside".
 
 The `actorOf` method of the classic `ActorSystem` is typically used to create a few (or many) top level actors. The
 `ActorSystem` in Typed doesn't have that capability. Instead, such actors are started as children of
-the user guardian actor or children of other actors in the actor hierarchy.
+the user guardian actor or children of other actors in the actor hierarchy. The rationale for this is partly about consistency. 
+In a typed system you can’t create children to an arbitrary actor from anywhere in your app without messaging it, 
+so this will also hold true for the user guardian actor. That noted, in cases where you do need to spawn outside of this guardian 
+then you can use the @ref:[`SpawnProtocol`](./actor-lifecycle.md#spawnprotocol) to spawn as needed.
 
 ## become