The Shaman GCD is 1.5 seconds, but totems are on a 1 second GCD. It sounds like you're suggesting dropping 4 or 5 tremor totems at one time. The problem with this is that they would all pulse at the same time, and therefore wouldn't be much more effective than one single totem. Since they pulse once every 3 seconds, most people drop 3 totems at one second intervals, then an earthbind or something. I use my big totem macro for tremor totems, but I also have them on a separate key for when my totems are being targeted.