What determines which player the zombardiers target?

In Junkenstein's Revenge, there is a Zombardier enemy which attacks players with blue energy projectiles. It sometimes feels like the Zombardiers collectively choose a single player to shoot at for the entire game.

I've had rounds where the Zobardiers ignore me when I'm standing next to them, while other times they've gone out of their way to shoot me from across the map.

What determines which player the Zombardiers target in Junkenstein's Revenge?

I forgot to respond to this after this year's Halloween event.

Based on observation from a lot of games, the Zombardiers target whichever player/entity does the most damage during the first 3 mini-waves (center, left, right) and will only fire on other players if their primary target is out of line of sight or if their primary target dies. It's not clear how they choose a new target after their target dies.

This also resulted in a few interesting games where the Zombardiers targeted Torbjörn's turret until it was destroyed.