Rake does not decide intercity. Number of rake does not matter. Intercity means it leaves from source and return back to source the same day , you are correct but its still intercity cause it leaves ERS at morning and cover to SBC before evening and vice versa.
There are lot of train already during that time from ERS to TVC ; And morning from TVC to ERS no extension needed. Snatching trains from CBE to ERS first of all is bad idea but during those time trains train to ERS from...
more... SBC was only island so it made sense. But extending further is dumb - totally