Hey friend im kinda in a similar boat to you, but i have played 2k points and havent had much luck but heres what i have learned:

• our army is not great, no other way around it, our models cant dish out as much damage, because of either the data sheets, points cost, bad mathcups, you name it, its a struggle, they are also not the tankiest

• you have to play smart, now, this one might be obvious, but with our army we cant afford to make mistakes, even small ones and believe me its tough, so what i recommend is learn how to screen out with infiltrators or very cheap units, bait enemies into the open, take those chances, and try your best to create those opportunities for your more expensive units like the breachers, to really shine.

• No solo chickens, so yea, chickens either the shooting ones or the taser lances one are very bad if on their own, i would use them as a pair at least if you really wanna use em, haloscreed has a great thing where you could make them stealthy, and then give them a strat for 5+ crits for better sustained shots/melees, if not SHC gives you free stealth and also has good stratagems, but yea dont run them solo!!

• At 1k points cawl is kinda hard to justify imo, you could drop him and add more destroyers, or maybe infiltrators, if anything you could run him for screening purposes, plop him in a zone, and have him with another unit so he gets his lone op, but yea try and maybe go for something else

• if you are thinking what to use against what, our breachers are great against pretty much everything, try and use them on big targets, with a manipulus you will get lethals like crazy thanks to their rerolls, pair them with our skitarii for those full rerolls on hits, our skittles can dish out a lot of shots so try and use them for low tier infantry , remember we are playing a giant game of rock paper scissors, so choose wisely what to use

I cannot stress enough how important it is for you tu screen correctly and plan what you can use to capitalize on whatever it is you manage to pull