From the sound of it, the older one was not on board with this scheme whatsoever. The "horrible" sound was probably a chicken growl, meaning "warning, leave, or I will pound you into the ground."
So yes, the small chick was scared speechless.
The age difference is just too much. But be on the look out for one of the others that may be much more laid back than any of the others. You could try it again if you can find a real easy going candidate.
Bantambird has a good suggestion. Why not bring the cage indoors and let the chick hang out with humans for a few weeks until it gets some size? Human companionship will work in a pinch to placate a lonely chicken.
If it is a solo chick, can you have a little house chicken until it is big enough? I have had solo chicks hatch from botched hatches, and since my DH is nearly homebound, he played mommy with the little one until it could join the others. It means petting and snuggling with them often. We had a hand mirror in there and an old mop head for it to hide under like a mommy hen, and my mother in law made diapers for it.....
that sounds fun and amazing! I will do that