Stop & think about this. Years ago the assignment cards were hand made & the staff at Alarm Assignment & Planning took the time to figure things out. They made plans! Part of the plans called for creating a response to help Staten Island with an ample response that would not create a large amount of relocations. Remember, if you have an old assignment cards, look at the dates that they were issued.
Check the back, sometimes the dates of changes were written on the rear of the card. Some of those companies on the card might have been disbanded or relocated since then. Years ago, Engine 154 in SI was near the ferry terminal, today its in the Travis section.
Lower Manhattan in the City Hall area also changed! So you have to keep this in mind when reviewing old documents. Example - Engine 6 today is in Engine 32 fire house. Engine 32 was disbanded. Engine 4 was disbanded & then reopened into another station. Engine 10 was relocated, & Engine 29 was also disbanded. There was an Engine 12 near where 1 Police Plaza is. Engine 7's second section was disbanded in 1939.
Also depending upon the year, there are newer companies on Staten Island since the big brush fire in 1962. In 1960 Engine 165's station was open. The first new company since the late 30's. The other new ones are 154 redeployment, & the new stations for Engine 166, 167, & more recent Engine 168.
Today, the assignments are computer generated based on the information in the computer. Such as a Brooklyn response to Staten Island - Engine 284 might be second or third due to the bridge (Bklyn side) but if they were 4th due they would not respond because they have Sat 3 in quarters. There is a restriction in the FDNY computer that would stop their initial response.
The Staten Island grid system was established in the 70' or the 80's because of the problems finding street locations on S.I. - only a few numbers streets. It used map books that were produced by the NYC Planning Department.
Some of the companies south of the Staten Island Expwy have the biggest first due areas in the city with over 300 boxes, & numerous dead end streets, in addition to numerous private developments that are hidden from local streets as you drive by they have there hands full. Only adding more head aches to the local companies.