Halo Wars 2 Artwork leaked.

So more news on Halo Wars 2 (Finally!) on twitter today;
Earlier today/tonight/wherever the time was some Halo Wars 2 artwork was revealed over twitter and it BLOOMED over the halo community, mainly receiving positive feedback, new theories. Now it involves the new brute we saw with an army behind him, with a large group of spartans charging at them. in the background we see some weird (Promethean looking) Ships with something we probably did not see coming: The Ark. So this confirms (99%) that this is before the events of Halo 3 (Maybe 2) because the ark is intact, but my theory is that this is how the Covenant found intel on it in the first place. Picture is below, so feel free to look at and theorise.