The perfect team.

[Targan]

I think the movies sometimes answer this question well. Take the series Firefly (and the accompanying film Serenity). Their team worked really well - Leader (good in combat, war veteran NCO type), XO (excellent in combat and good tactical ability), Pilot (okay he is pretty specialised but incredibly good at his specialty), Hard-Core Hitter (hand to hand and ranged combat expert and REALLY loves fightin' and shootin'), Mechanic (sadly useless at anything else except bonking but extremely sexy which I think is important), Medic (actually an absolutely first rate trauma surgeon), Clergyman (skilled at negotiation and always has something nice to say during funerals) and finally Government Modified Psychic Assassin Chick (the title says it all).