no matter what i do i can only bring them down to two guys before i die and it's completely brought the progression down to a halt is there a way to make the fight easier?

If you're having trouble with the second big ambush in the desert, it probably comes down to you not being prepared. Conserve supplies. Don't use the healing items outside combat, you have a healing skill. Heal and energy up before you enter the fight. And then alternate between the wide and narrow attacks, getting a general spread of damage in, taking note of where it lands after a couple attacks and quickly sniping whoever's lowest with the single-hit attack. Time your energy re-ups and heals strategically. Occasionally you just get bad luck too, so I'd certainly save before the fight, but if you've got the basics covered you should be able to get it in two or three tries at most.