Question About Bleach SS

So I have some questions about Bleach souls. Recently I picked Bleach back up and noticed what I believe to be plot holes. These are spoilers for anything before episode 32. So we established that souls don't need to eat or drink and don't age when Chad met the parakeet kid outside SS. But we see Rukia and Renji which were confirmed souls that started out young stealing water and aging. I'm very confused and need answers so if u have any theories or just want to add your two cents please do.