4 strong chicks and 4 weak ones?

my girlfriend and I got chicks from farm and fleet about 2 weeks ago. I think they have everything they need, but am wondering if there's not enough space?

there's 8 of them (about 2 weeks old, maybe 3??) and they are in a 27 gallon tub with wood shavings, their water, and food. 4 of them are very strong and active. the other 4 seem to lay around more often.

we took the 4 out to explore and stretch more without the other 4 strong ones getting all over them, but they seem to have less function in their legs, or even interest in moving around. a couple it seems like they can't even fully stand up on their own..

is there a lack of space and they need to be separated so theyre not trampled by the strong ones?

thanks for help and advice!