So it would be faster to just stack these up by hand, as I don't see any mortar in those joints. That's a pricey machine that just stacks blocks.
So looks like they are depending on the quality of original concrete block manufacture that has perfect size after manufacture. Besides adhesion of the blocks, and closing air gaps, that mortar makes up for size tolerance issues.
And just stack them up, fill the cores with concrete, every 4 feet a rebar, mostly hurricane resistant base. The roof is another problem.