According to mimitchi.com, there are different growths in the different regional versions of the Tamagotchi Ocean. According to your chart there's no difference. Is there a difference?

No there is no difference between the 2 Oceans. Only the language.

Yes, I agree with her.

Actually there is, it just changes a few characters around. :)
Japanese version:
http://www.mimitchi.com/ocean/pops/pop01.html
English version:
http://www.mimitchi.com/ocean/pops/pop02.html
Tama-Zone has the Japanese version. :)
http://tama-zone.com/index.php?showtopic=20038