Yamato might just be a rental type character like Oden. If not, she's getting surpassed by Sanji eventually. Oda delayed Jinbei from joining until the M3 were gonna be clear of him for a reason imo.
Is her strength devastating to the series? No, it's cool to have a strong character joining the crew this late into the journey.
Is her character defining trait being an obsessed Oden fangirl devastating to the series? Yea it's pretty annoying to read weekly, I can't imagine it'll get any less annoying with more panel time.
If her strength bothers anyone they're either still teenagers (and that's ok) or haven't worked a day in their lives, there's more pressing matters in life than a fictional character's strength.