Mycroft, and his younger sibling both have thier own qualities. Mycroft is a genius abstract thinker, who can reason from an arm-chair, just as well as Sherlock could, had he been running around London all day. Sherlock however, is a gung-ho active man, who uses his brains, but also uses his energy when it's needed. Both Sherlock, and Mycroft have thier own useful techniques. Sherlock's just more active to prove his. To say that one brother is greater than the other is tom-foolery.