: The problem is that I could envision most of Reach's armor sets existing.
: There were a few with thin justifications, like the helmet specifically
: designed for forward observers, but at least only the helmets had an
: obscene number of variations.

: This is an interesting question I've been thinking about, and as it turns
: out, an Ark is harder to keep running than Battlestar Galactica and
: Homeworld made it look. Warships exist and operate within the support
: structures that built them. They need the shipyards and drydocks that
: built them to do extensive repairs, and they need the factories to make
: the spare parts that keep them running. Those factories, in turn, require
: the factories and refineries and mines that supply them with materials,
: and they need the farms and the medical clinics that keep their workers
: alive and healthy.

: Can you shrink that massive industrial supply chain down far enough to fit in
: a ship?

We haven't really seen enough of Infinity to really be certain, but I'd like to imagine yes, with the caveat that they're going to have to stop at some points for heavy water for the fusion reactor, or to mine ores to use in whatever processing plants they have aboard. Those sorts of things definitely benefit from existing infrastructure and support fleets, but especially with its additional science/long-term mission plans to decommission the Halos I think it's probably got long-term mission operation capabilities, certainly beyond the "built for war" specifications of the war's Covenant ships. Worst case scenario, it's got those Frigates it can scrap for parts and power.

Sustenance seems like it would be the least of their issues, although again we don't really know exactly how far the UNSC's hydroponics or advanced microfarming techniques go.

Really with the Infinity on the run at the end of Halo 5 you can almost imagine they could do a Star Trek Voyager sort of situation where they have to run on reduced power and scavenge for lack of a supply line, although I can't imagine that being a major part of any video game.