uhh...what? objectives? get far away enough, drop the hatches, and make advantage of your 30" range. if you need to assault objectives, railhead submunitions make a mighty big mess of clustered units.
look at it this way. theoretically, you have a rock-paper-scissors model for 40k armies. theoretically i say, since it's not a perfect representation. however, for demonstration purposes, it suffices. you have 3 general types of armies, static, mobile, and drop. static beats mobile, since static naturally has more firepower then mobile, and mobile has to cross that fire zone before it can bring its own weapons to bear. mobile beats drop, because drop is static, without the firepower of static, so mobile can close and annhilate in detail. drop beats static, because drop negates the long-range advantage of static and gets to effective range without having to close the range first.
thus, you want to play mobile. for tau, that means fishwarriors and railheads. your pie plates aren't the imperial guard's, but the railhead submunitions can still lay a lot of hurt on a deep striking unit. if the chaos player drops on objectives, he's HAD to split up his force, so you're likely looking at 200 points or so on each objective in a 1k game. if you can bring a devilfish with warriors, a railhead, and some xv8s, which you easily can send to each objective in 1k, you are outmatching him 2 to 1. pie plate him, pulse rifle him, then finish him with the xv8s. the trick is to take out their landing zone before they can reinforce. you're not guard, you can't spam the area and force him to take mishap rolls wherever he lands. you have to play cavalry to the rescue. tau are very capable of frontal assault with their firepower, you just need to remember their mobility and choose where to apply that frontal assault firepower, because they don't have the bodies to sustain it. pick the schwehrpunkt and apply heavily armed mobile force to it such that it cracks as soon as the force fires a round.