Complex sentence: McCormick was as an assistant coach under Norm Van Brocklin with the Minnesota Vikings and under Vince Lombardi for the Super Bowl Champion Green Bay Packers.
Split into simpler sentences: McCormick was as an assistant coach under Norm Van Brocklin with the Minnesota Vikings. After his time with the Vikings McCormick was an assistant coach under Vince Lombardi for the Super Bowl Champion Green Bay Packers.