How to play local coop in Victor Vran with two X360 controllers on a Mac?

Launching Victor Vran on a MacBook Pro running OS X Sierra with the latest version of the 360 Controller Driver from https://github.com/360Controller/360Controller/ installed, I start a game of local coop, but despite both players being set to use Controller 1 and Controller 2 respectively, I cannot control both characters with the controllers.
One character moves, but the other does not move at all.

How can I get it to work?

For some reason, the game assigns different numbers to the controller than the OS X driver does, so your controllers might be controller 2 and 4 in-game, instead of 1 and 2 in the OS.
Try different combinations of controller numbers, until you find the one that works.