It is interesting to me that thematically, the Yerushalmi is far less textual or objective than the Bavli, for starters. Yerushalmi many times is concerned with observing people’s conduct and codifies observations of what people are noheg to do. Tosafot very often reads Ashkenazic minhagim and more Yerushalmi-based practices into the canon, and AhS, like Tosafot (and even the Ra’avad), is often concerned with paskening in a less textual manner. AhS is concerned with what people are noheg to do (see his limmudei zechut on women’s hair covering, hashma’at kol on shabbat, bedikat tolaim, cantors using tuning forks on Shabbat- which the MB was against, eruvin, etc.) MB seems to be closer to the principles inherent in the Rambam’s approach, IMHO.
AhS is very much lekula in his psakim, and the very fact that he was a communal rav and not a rosh yeshiva is probably a testament to this fact; AhS is more concerned with popular practice than a more academic style, and he has fealty to established custom, even when it is in conflict with theoretical halakha. The Gra was very opposed to this type of approach, hence the fact that the MB is very much reliant on the more Talmudically-based Gra in many areas. If my theory or observation is faulty, I’d accept other views.