Duelist: Jett (Jett is just so good as a duelist, trapped in a sticky situation? Just dash out. Want to rush a site? smoke and dash in. The only problem I can see with jett is that she cannot contribute to the team that much, its all about the solo plays).
Controller: Astra , this doesn't need any explanation at all. Viper is close to astra as well because of her damaging abilities but I think astra is slightly better.
Sentinel: Killjoy ( no explanation needed for sure) ,
Initiator: Sova ( Gathers a lot of info + shok dart are useful af) Breach and skye are good as well but won't be relevant after they receive their flash nerfs