Your report on Adrian Furnham's research claims that the least intelligent students prefer coursework to exams. But although Furnham has reported a link between self-assessed intelligence and assessment preferences (in the Journal of Applied Social Psychology ), his study in Learning and Individual Differences (to which you refer) failed to replicate this. What he found was that personality correlated with some types of assessment. For example, extroverts prefer group work and oral examinations.
My own study of psychology students found that motivational factors related to coursework performance - that is, people who enjoy effortful thought gained higher coursework grades, while procrastinators showed less evidence of reading and were disproportionately represented among those who missed deadlines. Furthermore, coursework grades were positively correlated with exam grades. These results are inconsistent with the idea that coursework benefits "plodders".
London Metropolitan University