I'm not sure if these are the only models you have (I hope not), but I would run the scions as a 5 man squads and drop them either on objectives or near vehicles with meltas attached. any knowledgeable player will focus these out as they're the only decent shooting troop choice we have.
For the Torax I would lose the gatling cannon and grab the battlecannon.
Lose the track guards, and plasma sponsors on the tanks and run all 3 of them with battlecannons and lascannons. This will give you plenty of breathing room so you can snipe tanks and such at a distance without having to get close. Also make sure you run them as catachan so you get the reroll for your main gun.
On your guard squads grab a special weapon dude, make sure to give your Sgt a boltgun so the squad can not only capture objectives but also give you decent firepower. I would also run that batalion as cadian for rerolls when standing still.
Your army is starting off strong but you need more tanks, arty (mortars/basilisks), and above all meat (lots more guardsmen)
Hope this helps.