Aside from passengers to Liverpool, in former times "passenger" trains could have as much capacity provided for mail, parcels, news (not just morning papers - weekly magazines too), etc, and having them over in Central made the transfer to further services, either by porters or shunting the vans over, much more practical. This was behind the continuance of a number of secondary services and unusual through trains. Even distribution of these locally within the city could be better from a large, quieter station like Central rather than through the crush at London Road.