Top tiers:
Assault - Blitz Markov / Parnell
Medic - Caira / Rouge Val
Support - Cabot / Tech Hank
Trapper - Griffin / Abe
Simple explanations:
Blitz Markov - Great dps. Rifle when laser is out of reach. Place mines on downed hunters and around map. (Damage dealing hunter)
Parnell - Great dps with ability. In with shotty. Out with rockets. (Damage dealing hunter)
Caira - Speed boost to prevent monster shield regen. Healing can be difficult. Always rotate damage and heals. (Offensive healer)
Rouge Val - Poison dart then heal. Rifle for added damage. Self-heal if needed (Defensive healer)
Cabot - Focus on 2x damage. Dust is helpful. Wall bang when possible (Offensive utility)
Tech Hank - Charge shields out of combat. Orbital drill a stationary monster (Defensive utility with high burst damage)
Griffin - Harpoon harpoon harpoon. Place sound spikes around map (Defensive CC)
Abe - Always tracking dart the monster. Stasis to counter monster mobility (Offensive CC)
Core team combinations:
Parnell, Rouge Val, Tech Hank, Griffin
(I would only sub one of these hunters out for another listed)