: Destroyed, as of Halo 3.
: LOFTUS! FRONT AND CENTER!
: Did, or did not, the journey to the Ark take several months?

The entire Halo 3 campaign spanned November, 2552 to March, 2553. The one way trip to the Ark from Earth was Nov. 17, 2552 to Dec. 11, 2552, so 24 days, or about a month.

Lots of Inner Colonies were destroyed. Part of the problem with fining which ones is we don't have a definitive list of what colonies are Outer and which Inner.

: If so, then there was plenty of time for Loyalist factions to continue their
: assault on Humanity. If the Cole Protocol was breached during the attack
: on Earth, this would only have made the Covenant's job easier.

Remember too, that the Covenant ships have Luminaries on board (or essentially Forerunner relic detectors) and they knew Earth had relics before they got there, so they could easily find other Inner colonies that had Forerunner artifacts and such, probably many of which did since it seems the Forerunners occupied a lot of the same territory back in the day that the humans and Covenant occupy in the 26th century.

: Why not?

: With what? And do you mean "Look over" or "overlook"?

: Like I said, I'm not sure that it did. The fact that High Charity had a fleet
: that size for an escort hints that the Covenant weren't hurting for ships,
: even after the destruction of the Unyielding Heirophant.

The Prophet of Truth considers the loss of the Unyielding Hierophant and its fleet "only an insignificant setback" at the end of First Strike. Doesn't sound like the Covenant were missing much.

: And if you are correct, it's a retcon from the original intent of the
: Covenant's size.

: I don't think that the above sounds very reasonable.
: It kind of presumes that the whole of the Covenant empire is nomadic, and the
: only proof of that is High Charity (Built around a Forerunner spaceship
: and an asteroid) and the supply/harvesting we've seen that fuels the
: Covenant war machine, which has to be nomadic because the Covenant are
: fighting so far from home. There's also been the Jackal pirates, who hid
: in asteroid fields because that's the easiest place to hide.

: So far, all evidence in favor of a nomadic Covenant has been pretty
: circumstantial. And why let perfectly habitable planets lie fallow?

High Charity was mobile I suspect more to keep its location and existence safe from enemy threats. It was the seat of the Covenant Hegemony. It was mentioned in Contact Harvest I think that there are Covenant members who never get to visit it and that it's an honor to get to go. The Covenant still have lots of member planets such as the actual homeworlds of the client species, plus anywhere they've found with Forerunner relics on them.