Well the first thing to consider is that the
wp_enqueue_scripts action hook fires before the filters on the page/post content are run.
So I would add a function to the
wp action hook and test the content for oembeds there.
add_action( 'wp', 'your_oembed_test_function' );
//earliest reliable hook to get $post variable
//do your tests with $post content
if( $oembed_exists_results ) wp_enqueue_script( $your_handle );
Because WP fires before
wp_enqueue_scripts you will be able to choose which scripts/styles you want to show based on which oembeds you find in the content.