staggering the joints will stenghten whatever your sheathing, if its the roof the roof becomes stronger. just because the building is brick it doesnt have anthing to do with the roof. floors, walls, and roofs are all individual systems that act as one. the stronger one is the stonger they'll all be.
besides, by staggering the joints it wont telegraph through the roofing material as much. on cold days the easiest spot for heat to escape is through the joints, this is why in the morning if you look at newer convential roofs with plywood sheathing you can see a grid pattern from the plywood, its the frost melting at the joints