but Mumbai has EMU's, which also means most of the passengers in WR's network are actually those who travel in locals :P I sometimes doubt a single zone can manage operations of entire Mumbai while also handling rest of MH, already CR is getting stretched thin here.
many people suggest that the region around Mumbai should be separated from from both CR and WR, and operated as single entity, that would finally allow them to focus on EMU's more without bothering about other areas, though that opinion isn't very popular with people who stay there. :P