I think its not a good idea if CH4 have picked children on the basis that they will probably kick off - that is child abuse on CH4's part.
I'm not anti the idea but I think everyone should have been the same age. The older girl's behaviour was disgusting towards the younger girls. I think the boys, although fairly helpless in practical terms, came out of it quite well which pleased me as boys are IMHO looked at negatively by society. They certainly weren't wilfully cruel.
How would my sons have got on.
One would have teamed up with a nice quiet boy and avoided conflict and looked after each other and worked out how to cook.
The other would have played, eaten sweets and been involved in scraps, probably broken an arm or a leg (his own) and then cried for the rest of the time he was there because he was hungry or everyone was being mean!