@Koochi-Q I think it depends on the situations.
Best flushing team I can think of would be Caustic, Bang and Bloodhound. Gas+Smoke+Bloodhound ult and scan. Good luck surviving that coming at you unless there is a major skill gap.
I still think Life Line is the best at reviving mid fight. Simply because you don't have to have a teammate out of the fight.
I'm not a huge fan of sending 1 teammate in to 1vs3 an enemy squad. If you're going to push into a building with enemies all 3 should push in together. When you got in 1 by 1, you tend to get focus fired on.
Gibi pairs really well with Horizon, black hole + Gibi ult is devastating to enemy teams.
Caustic has turned into one of the better aggressive legends. The Tridents have made him really good at pushing enemy squads. I was I've come very close to a triple triple with him and the tridents.