So the Covenant had no chance of winning in the first place. Thus my arguments are entirely pointless, and the purpose of this thread is null. The Imperium wins.
It was a joke. Chaos? Magic? Insane technology caused by tens of millenia of development? Put that against three factions, of which two have been functioning for maybe 2k years each, with only one actually being competent for 2k of those years. The other was in power for maybe 100.
Covenant is obliterated.
Humanity is vaporized.
The Flood probably just kind of... Float somewhere. I'm sure they'd do some damage, but not enough.