If the brooder is big enough, it should be fine.
But pay a bit of attention to how many, and what ratios.
50 big chicks, 2 little ones? Bad idea.
3 of each age? Probably fine.
3 big ones, 10 little ones? Even safer.
One time, I had a brooder 4 feet by 7 feet.
On Wednesday, I got 16...