You are right I think the only reason which stops them from this is the fact that both the trains run daily. Imagine the foll scenario if the trains are made independent
13351/13352- 6 rakes x 19 coaches per rake=114 coaches
18189/18190- 6 rakes x19 coaches=114 coaches.
Will this be possible ??? As of now with the amalgamantion there are 6...
more... rakesx 22 coaches= 132 coaches. If they try and run this as independent trains not sure whether they can accommodate so many rakes/coaches .
But in the long run the ideal solution is to run them as independent trains.