tau have a significant and quite lengthy assault phase. all of their jet pack jumps take place in that phase.
I know what you're thinking pax, but i've seen it in action. Yes, it can go fast. but there is still a minimum amount of time to decide all those things, roll all those dice, look at all those charts. roll more dice, make some attack rolls, roll save, roll damage, see where it explodes on the board, then move on to the next pair of fliers. two armies with just two fliers each could have 10-15 min dogfight phases every game turn that accomplish little to nothing. or it could go fast. i'd just rather play the actual game.