First you need to define exceptional children. Are you talking about those with mental impairments? physical mobility impairments? sight impairment? hearing impairment? emotional impairments? gifted?
Each of these different kinds of exceptionality brings its own challenges.
One can have exceptional children with a wide range of difficulties. I have known exceptionally gifted children who could not focus on simple problems, their minds were elsewhere. I have taught a few exceptional teens who had great difficulty listening and analyzing.
On the other end of the spectrum, exceptional children who are functioning cognitively below the expected age level have again, a wide range of difficulty, ranging from social, personality, listening, emotional and anxiety difficulties, and even neurological processing difficulties. It is difficult to generalize.
You can use the above in generating a task analysis on whatever task you choose, but in reality, the difficulties vary greatly child to child, somewhat like in ordinary children.
Bobpursley explained the concept of exceptional children much better than I did. Each child is an individual and teachers must recognize and teach each student as a unique person.