What would your ideal apparatus fleet be for a fire department about the size of Calgary's (say 40 stations)? I'd go with:
-40 engines
-12 aerials (4 single-axle 100' ladders, 4 100' platforms - something like the King Cobra, and 4 134' Bronto platforms)
-5 rescues
-4 HAZMATs
-4 interface engines (something like the Timberwolf)
-3 industrial pumpers/tankers (3,000 gal. tank with a large capacity monitor on top - serving both the wildland tanker and the industrial pumper role)
-3 air/light
-2 squad/water rescues (smaller units, say on a 5500 chassis)
-2 fire support (carries salvage materials, tools, fans, etc.)
-2 FRP/RAC
-1 rescue support (carries specialized equipment and the bulk rescue items)
-1 HAZMAT support (carries additional equipment, decontamination supplies, and transports collected materials)
-1 command post
Obviously I haven't accounted for spare apparatus.