The numbers work out the way they do because of United Express.
United has been crushed in revenue lately because they fly RJs from major cities to their hubs domestically, where AA and DL all fly mainline.
When it comes to International, United has the big metal. However, ever since United cut their domestic mainline feed and replaced it with RJs, UA has been playing catch-up.
United has way more RJ flying than its competitors, and its only now that UA management is realizing it is hurting us.