Fenchurch Street in the evening peak used to be 1,2,3,4,1,2,3,4 but I see that this is no longer the case. However in the morning peak it used to be arrivals 1,3,2,4,1,3,2,4. This was to avoid two consecutive arrivals on the same island platform causing congestion and reducing the danger to passengers from open doors in the days of slam door stock.