I'm not sure what you mean but you HAVE to be in MB and do the quests or you won't get to Mooshu.I personally see a lot of people lower levels in MB but the way I have played is to do every single quest in each area,such as doing Triton undersea area in Wizard city before going to Krokotopia and all the quests in krok(except tomb of beguiler since people have told me to wait til lvl 48 for that one) so I was in mid 30's when I finished MB.Others seem to want to unlock further areas sooner so they hold off on side quests.IMO there is no such thing as overleveled as I have seen and been helped by players much higher than myself in every area so just enjoy the game at your own pace.
i dont know why you posted this but being overleveled is good! it means you have been paying atention and be willing to spend more time doing side quests. P.S. when i got to marleybone i was level 32 aswell!