The Jedi have had a troubled history in Galaxy of Heroes. They saw some use under a zeta Qui-Gon Jinn lead for raids, but for the longest time were the butt of many jokes. That all changed with the rework  of Grand Master Yoda. He received two zetas. Shortly after the rework Bastila Shan was released, making the Jedi a truly viable arena team. While Darth Traya still gave the team troubles, that concern evaporated with the release of Jedi Knight Revan.
Bastila Shan. A key component to any Jedi team whether she is a leader or not. She is often used as a second lead to make two Jedi teams in Territory Wars or Grand Arena. However, she has deadly synergy with Grand Master Yoda, who can spread the buffs to the team that Bastila's Rally gives to him.
Grand Master Yoda. While his lead saw a brief use in Phase 1 of the Heroic Sith Raid, he is now an amazing character in any Jedi squad.
Jolee Bindo. A robust healer that calls assists and resurrects fallen Jedi. He is a key component under Jedi Knight Revan, as he also adds 10 speed to the team.