If the tall rectangular block of Orsanmichele looks to you more like a grain silo than the church it's supposed to be, that's because it has been used as both.
The rectangular Orsanmichele was used only as a church.
mnli hypothesis: The rectangular Orsanmichele was used only as a church. premise: If the tall rectangular block of Orsanmichele looks to you more like a grain silo than the church it's supposed to be, that's because it has been used as both.