The Covenant (Halo) vs The Grand Imperium of Man (Warhammer 40k)

[Fallen Angel]

My point is that the covenant is only a single tier above the UNSC, enough that they can smash the latter's ships with ease, but with with effort the latter can kill the ships of the former. (Thank you retconned space battles.)

The Imperium of Man has firepower that is generally agreed upon as one 'tier' lower than the Galactic Empire.

The Galactic Empire is way above the UNSC.

Thus, the Covenant is fairly below the Imperium, let alone Necrons, with the Nids being a Out of Context Problem for the Covenant. (If the Covvies had problems with the flood in space, then they will loathe the Nids.)

The only locals I can accept having trouble with the Covenant is the Tau, and even then the Tau are a few 'tiers' above the covenant.