Okay, so you have a combat-oriented Guardian with a Kyshakk whom you tend to put in front because of its health? And you shoot for the artillery before the front line? Great.
What I don't see you mentioning, however, is maneuvers. Properly taking advantage of a wall or a door or even a dumb pillar can often mean the difference between life and death, as the blocked line of sight forces your enemies either to choose a different target or waste valuable action points trying to set up a clean shot. In Grosch, I recommend occupying one of the buildings and using the door as a chokepoint. My favorite fight there involved me splitting my forces and luring an entire enemy patrol into the building with my ranged creations. While the rogues were practically falling over each other to squeeze through the door, I walked up from behind with a pair of clawbugs and calmly disemboweled their support units.
Of course, this isn't what I tried the first time, and I admit that the first time I lost. I guess my final word is that if you lose a fight and then try it again the same way the second time, you're playing the game wrong. Innovation will always carry the day. Anyway, good job on making progress.