You are forgetting one very important thing. The Charger and truck each have to move an added weight in addition to itself (as in air for the sub drivers). It takes less work for the truck to move that load. Ask the truck and Charger to move 1000 lbs. in addition to itself, and you get a slightly better analogy.
A better analogy would be two trucks, one 20% larger and more powerful than the other, and with better brakes.....then ask them to start and stop with the same loads.
What you are trying to describe is impulse response and/or decay of the drivers, which has a lot of factors......stiffness of the spider, strength of the magnet and motor assembly, response and power of the amplifier....and a lot more.
A 10" driver has to move much farther to move he same amount of air as a 12" driver.
