Help building G3 team

I have recently got a balloon luffy and will soon evolve him to G3, but I don't know who to put in the team. Currently I have: 41 Zoro 5*, 34 Smoker 4*, 29 Goldenweek 4*, 37 Zeff, 15 Sanji 5*, 28 Chopper horn point, 34 Alvida 3*, 11 Miss Valentine 4*, 46 Ussop GP, 37 Shanks 4*, 15 Nico Robin 5*, 25 Nami 5*, 35 Don Krieg 3* + Django Mr 5 Mr 2 all unevolved and lvl 5

G3, GP Usopp and from then on try to get as much HP and Dmg as possible, I can suggest Zoro 5*, Alivda (evolved) and prob Shanks or Nico Robin

Depends on what it is that you want to achieve. If you are going for mihawk I'd use G3 zoro GP Ussop evolve Alvida and try to farm arlong. But like MigicDodo said put your strongest units in with G3 to get the most out of him.