How to insert nodes into a Views result In Drupal 7, I have a View that works great but I'd like to add a few nodes into the result arbitrarily outside of the scope of the View.  

Basically, let's see the View returns Content Type X, I want to include a few nodes from Content Type Y that are in addition to whatever the View generates from Content Type X.

My preliminary thought was to use hook_views_pre_render but I'm not convinced that is the best solution....yet.
You may want to use hook_views_pre_execute (see example) or hook_views_post_render() where you can add arbitrarily content (new rows or html code) into the view to fake the nodes.

Please check the following code example to give you some idea.

You may also compare how other Views-based modules doing non-database query results, such as Search API Views or YQL Views Query Backend.