In salt flats you have to tackle 2 main issues one your lack of water which means if a sing fire starts you either have to take your already limited time to put it out or you will lose immediately and two the opponents insanely strong defense. There is two ways to destroy it’s defense first simply brute force your way through it which is incredibly difficult but possible, or you could do it the smart way and cut off its supply chains and wear down their ammo which takes a lot of time to do.
And here is a tip from my experience don’t whatever you do ever accidently delete your water pumps as they are the only way to get water and for defense anything that kills them quickly from a safe distance like lancers and salvos and even mines in the later game. Try to kill them before the atraxes come and set everything ablaze.