This is currently the comp with the highest chance to win a lobby. Your best case is to open with 3 Piltover, either with early Ekko/Jayce or with the help of Augments. Keep an eye out for Augments that grant a free Piltover unit that might help you to enable the trait early. There are two paths that players like to take.
One is less focused on Piltover and prefers combat Augments like Pumping Up/Gotta Go Fast with Master Yi Legend. In this version you want to reroll for Jinx/Vi/Jayce with Level 6 and push towards Level 8 later to add 4 Gunner and other high value units.
The other variation is to run Pengu as your Legend and take HP Augments like Tiny Titans or Metabolic Accelerator. Here your goal is to for a large Piltover Cashout and use this as your win condition. You are not required to reroll your setup here, sometimes you can do both, but that depends on each game. If you find a Gunner Emblem you give it to Ekko and try to run 6 Gunner as another win condition.