Nutrollio: While playing on Surpreme Jerk Difficulty I just delivered cat litter then got a transmission of a syth attacking a farm. Turns out it's ambush. I have the latest gear you can get up the that point. Still the enemies one shot me, I stand no chance at all. This fight is grossy imbalanced and almost impossible on hardest difficulty. I don't know how to win this one.
A classic one! after this, the next time the guy in the radio say to you " is only a robot" you will be scared (and believe me, is going to happen).
Anyway, the trick is COVER and known which weapon to use. Probably you will be forced to divide your team in 2 or 3 mini squadrons, and deploy your best tactics, anyway, due the auto-saves you can reload a previous game before entering the farm for getting more ammo (and grenades and rocket launchers) or farming XP.
The battle here has lasers and normal weapons, so all the types of armors will be heavily under pressure (lasers will affects high conduit armor like the power armor, the normal weapons will be able to penetrate the light and medium armor), that is why your best items are not working properly, plus the fact that the enemies come from all the direction making hard to take cover (So, first objective is to clean one part of the enemies for getting a properly cover from almost all the directions). If the synth is able to kill your party in one shot means you current XP is too low, if the synth is able to kill you in 3-4 rounds, means you need to take him down quickly OR forced him to waste some rounds reaching your team (meanwhile you are able to clear one part of the enemies for getting a good cover against the synth) .
Another general tactic for this battle, if I remember well, the battle begin once one character approach to the center, so you can placed the party in tactical place, in my case I remember using the first branch and the small building (south of the area).
By the way, the game was balanced ONLY for the normal setting, that is why the description of the jerk setting.