> The first mention of there being hundreds of colonies was a timeline released in the lead up to the original game designed to fill people in on the universe so far.
This is a case of the licensed EU not agreeing with Bungie. That timeline, assuming it even still exists, should be taken with a truckload of salt because by the sounds of it Bungie either never got the chance to inspect its contents before it went live, or that things were added to it between their inspection and the publishing of the site. Either way, any of the contents could have been non-canonical and not in any way representative of the actual Halo story. The “800+” colonies that it outlined is an example of that. It was made up by someone in Microsoft’s Halo division for marketing purposes.
> Bungie doesn’t like to retcon (i.e., deliberately change previously established facts), but sometimes it’s necessary. Take for example the issue of the number of human worlds. The truth about the “800+” number? That was made up by a non-Bungie employee and never approved by us before the Halo: CE promotional website went live.
In a way, Contact Harvest wasn’t really a retcon in this regard because it didn’t change anything canonical about the colony numbers at the time.
> I believe there were other sources too but I can’t say for sure.
The only ones that anyone has ever brought up have been from the Halo Encyclopaedia and beyond. I don’t think Nylund was specific either.
17 colonies is probably too low for the war, even if we assume that it was originally a borderline cold war of the UNSC trying to outsmart and outmanoeuvre the Covenant, hiding from them among the stars and tricking them with false signals and fake navigation data banks, as well as the sheer vastness of space offering some sort of protection. However the Covenant would occasionally get lucky and find a Human colony out of the thousands of neighbouring systems that could also possibly hold Human worlds. The Cole Protocol (The actual protocol, not the book) sort of gave that impression with fleeing ships leading pursuers on wild goose chases in random directions, stopping the Covenant from getting their hands on NAV databases and with ONI somehow attenuating Earth’s early broadcasts whilst creating multiple fake sources. Several dozen colonies would probably be more reasonable. It’s only a problem if you assume that there is a battle being fought every month of the war, or even every year.
I mean if there really were hundreds of colonies, then the Cole Protocol itself was practically useless as the Covenant would be finding worlds by the dozen per year anyway. It makes the Covenant searching for NAV databases useless as they would seem to be getting on just fine without them. After annihilating the first hundred colonies or so, they could probably start guessing as to where the core worlds are from the layout of the colonies they have already discovered, yet they didn’t. ONI vastly misrepresenting the nature of the war to the general public also only really works if the number of colonies is low, and not in the hundreds. It would be a bit hard to hide the fact that about one hundred colonies are gone, as opposed to just a few.