I think you've somewhat confused adding FastRAM and adding RAM. Adding FastRAM (i.e. RAM other than ChipRAM) will boost speed on your A1200. The amount of FastRAM is insignificant as far as speed's concerned though. Still. You can never have too much RAM, although 32Mb FastRAM will take you a long way on an A1200.
(You could however argue a speed increase proportional to the amount of RAM if you're planning to use it as RAD-disks and such, but that would be a different discussion entirely, and wouldn't have anything to do with the perfomance improvement of the hardware as such).
