If Kakashi graduated from the academy at 5 years old. And he became a Chuunin at 6, then shouldn't Obito and Rin be 6-7 years older than him? Why are they the same age?
Is Kishimoto bad at math? Did he not think things through when thinking of Kakshi's backstory? Did he forget he did that?
Wouldn't it make more sense that instead of seeing Kakashi as a love rival with Rin, Obito would be more jelous this tiny boy was just so much better than him/ getting more attention? Was team Minato not his first team?