Position A: The Senate should defer to the president's choice of who he wants working under him.
Position B: The Senate makes an independent assessment of the candidates in light of their suitability to serve the American people, even if it means denying the wishes of the president.
The question here favors position A. Given the powers vested in the president (and his ability to veto any decision) it is favorable if the people working under him are appointed by him and unless his/her qualifications are questionable, such a candidate should be approved by the Senate to avoid any show-down with the president (and the possibility that he will veto the senate's decisions). A hand-picked team will also enable the president to work more effectively and will maintain good relations between the president and the Senate. Additionally, since these nominees will be reporting to the president and will be his chief advisers, they should ideally be beholden only to him and not to the Senate; that way the president can be assured of candid and unbiased counsel.