I’m sorry. Snipers are not Zen’s only counters. He might cause someone in your team to switch if he’s playing well and has the support of his own team. But that’s how it goes no matter the game.
If the Zen has the freedom and time to LOS the enemy tank and his own team is only focused on this tank, then this is a team skill diff. 1.5s is practically nothing among all the natural cover especially on these new maps.