Remember that the fans have to be placed correctly in a computer case. It's no use just bunging in a load of fans and hoping for the best as you may have the airflows from each fan in conflict resulting in just the churning around of the same hot air inside the case.
No matter how many fans you have in your case,the CPU fan will always be on. The CPU generates a lot of heat which can only be cooled by a direct heatsinc and fan set up. At idle the fan won't have to work so hard,so with cool and quite it will run slower. If you tried running it with the fan off,you wouldn't get much past the boot stage before it shut down. Whoever told you it doesn't kick in until needed was talking a load of twaddle. Perhaps he was confused with the change in speeds using cool and quite as you can hear the fan increasing rpm's when the cpu is getting hotter.