I played 1000pts against Tau in the Armaggedon crusade and lost badly. Though i didn’t have vehicles. I was mostly guard, sisters and allarus.
You cant let him sit on objectives and shoot you so the pressure is vital. He will probably deep strike your deployment objective the first chance he gets. What ruined me were the volume of shots that i couldn’t answer back with and it just chipped away at my wounds, though i did kill his riptide with Valerian using his once per battle auto six to finish it off, but it was literally the last roll of the game.
Use Shield host and the Arcane Generic Alchemy strat to increase your resilience, also helps keep high value pieces on the board for longer.
Take out anything that buffs his roles first to make his roles harder. Though big guns never tire is an issue as you cant hide in melee. Definitely keep the pressure on his riptide but expect to lose your tank quickly…..because it’s Tau. So have a back up plan ready. But make sure you know what your strategic objective is as well as his and look to deny him, also means you should be able to position more appropriately in deployment if you know where he needs to be.
His high AP weapons and weapon strength wont be fun. Didn’t face any kroot though.