Make sure they get the direct full strength drench dose, and when you hydrate them use the corid water mixture that you are treating them with. I would start giving the the corid water as often as you can via dropper or syringe. For the littles I usually hold them in my hand with their beak resting in the crease of my finger, drip the liquid into the crease and it will run down to their beak and they will swallow. A little time consuming, but it works well. Sick birds often don't drink enough, you've got to get the meds into them for them to work. Corid is really safe, it would be VERY difficult to overdose them, so I would not worry about that. I don't see anything that looks like wry neck right now. Coccidiosis can cause balance and muscular issues also, symptoms can vary some. They do look very sick, I'm crossing my fingers for you.