this "lag" you mention - describe it a bit more

Let me venture a guess: you're looking at your mains screen - you press jump, and you see your main jump and then the slaves jump about 0.5 seconds later ?

Yet, if you focus on a slaves screen, press jump, then your slave jumps right away, and your main jumps 0.5 seconds after ?

If so, then you are just watching the builtin delay, that wow has to equalize peoples connections. what you see, when watching one client looks like lag to you. To everyone else in the game, your toons jump at the exact same time.

Think of it this way: you press jump on 2 clients at the exact same time, sending the commands to the server - when the builtin lag passes, they both jump. The jump is then sent back to other clients for them to see.

Try this: fire up a second computer, and log your slave onto that. Place them facing eachother. Use 2 keyboards. Press jump on both, at the exact same time. On each screen, you will se the other toon jumping 0.5 seconds after the toon you're controlling.