Ok, I'll try to fit the Armyverse into the Timeline.
Since Zack confirmed this, there is no denying it, and there may even be an explanation for it.
Explanation: Both Rebel Moon films are set in a galaxy ruled by the Mother World, but we know that the Mother World does not have that much control.
The Armyverse films are set on Earth in a zombie apocalypse which, as contested by Snyder, was caused by the Xanadite species that is from Rebel Moon.The most logical connection is that Earth exists in the Rebel Moon universe but is not part of the Mother World system or has not been found by them yet, so they could evolve without interference from the Mother World.
Perhaps also, the Rebel Moon universe is the future of the Armyverse, as it was also contested in the Lost Vegas series, it would have a concept of interdimensional travel that would connect the two universes