/follow is a set routine in WoW. No way to change it unless you use software that will quickly get you banned, and even then I think it's about the same because the client lag is what it is. :P

Note that if you use your mouse on your main to control your alts (say, with Multiplicity or Synergy) make sure you have that same mouse on your alts. My alts have cheapie 3-button mice and my main has a 5-button mouse. This prevents me from being able to use my thumb button for targeting on the alts.