This is R.E.D. Modpack and it replaces Units.artdef file from the game.
Civilization VI R.E.D. Modpack
Note that it will break other mods that use the Units.artdef file.
How to install:
– Download, unzip and pate the file to Steam\steamapps\common\Sid Meier’s Civilization VI\Base\ArtDefs folder replacing original one
– So you should backup first! You may want to uninstall.