A new venture start-up team often consists of the three (or four!) musketeers ...
... each with a distinct role and expertise.
Three is a good number for the senior management team ... more than three people and the communication channels start to become too complex; less than three and the workload starts to become overwhelming and complex.
The General Manager (or President) ... keeps the team together and moving forward; acts as the lightening rod when dealing with the investors; may be the initial finance manager for the venture ...
The Product/Operations Manager (or VP - Engineering/Operations) ... focuses on developing and delivering the products and services ...
The Marketing/Sales Manager (or VP - Marketing/Sales) ... focuses on business development, customer attraction and satisfaction, and most importantly, generate sales ...
The Finance/Accounting Manager (or VP - Finance) ... if the General Manager is not a good "numbers" person, the team may need at least a part-time finance manager.
After the venture is moving forward, this senior management team can be expanded splitting the Product/Operations and Mareketing/Sales positions into two.
A good team is a cohesive entity focused on what is best for the venture and its customers ... one for all, all for one. A good team is comprised on individuals who are competent, have complementary skills, and collaborative styles. Together the team is purposeful, passionate, and persistent. Together the team is focused on earning a profit solving customer problems better than the competition.
Also, See: Teamwork Rules of Thumb