Attacking with T'au is extremely difficult in any mission. We just aren't as mobile as many other armies. If you really want to benefit from all the aura effects our army gets, then you pretty much need to keep your whole army in an 18" diameter circle blob, and if you want to move and retain the firepower of some other armies, you need markerlights(3 hits) or you need to use Master of War(I forgot which does which).
The days of goodly English is went
Ziss old dog still has a few tricks!