Comparison of rgda express with 17225 is really bizzare..Extension from bza to gnt is hardly an extension... People from Gnt anyway are used to travel to bza if it's a train journey...Also it wasn't by passengers demand, but operational reasons then.
17225/6 extension beyond bza will definitely leave lesser quota for bza/gnt areas because of heavy population in WG/EG areas, and it will be one of a connection.