If the juveniles are not "bite size", and will not tempt of the larger fish to swallow them they tend to be ignored. It's a judgement call on your part, and depends on the fish you have, but yes adults will not pay much attention to juveniles. Aggression is more about pecking order, and the little ones are no threat to the pecking order. Adults can chase very small fish if they trigger the predatory instinct, or if the very small fish panic but they usually ignore fish over 1".
On the other hand, you tank seems to have potential problems with the adults, so maybe you shouldn't be adding any fish unless you change what you already have.
On the other hand, you tank seems to have potential problems with the adults, so maybe you shouldn't be adding any fish unless you change what you already have.
