"There are three types of mathematicians, those you can count and those who can't". A bad joke. But when I studied algebra, I sometimes felt a "dubious, shady glance" was needed to see the "impossible structure".
Why with reading difficulties can come other cognitive strengths is excellently explained in this article of the Scientific American.
Maybe it's a kind of frogs and birds trade off. People who have difficulties digging in the details think differently and understand the big picture better.
