Okay so last night I stumbled onto this thread and it got me thinking on how to do a Halo mod that does justice to the series and I thought up a few ways to do it.
Human Ships: Their ships are multipurpose warships that can do just about everything from bombard planets (marines landing or glassing) to almost all ships carrying a squadron of Longsword interceptors. Class-for class the Humans have a hard time keeping up with the Covenant in space-battles but will have a boost when it comes to planets [see further down]. While their ships aren’t very specialized the more expensive the ship the hardier it becomes.
Frigates
Prowler-Class: It is the Human scout. Fast and weak with maybe stealth somehow and a mine laying ability.
UNSC Frigate: It is fast and cheap and gains a small boost in planet capture.
UNSC Destroyer: It is a very well rounded craft, it is quick, well armored, and with its a more powerful MAC gun it is more powerful than a UNSC Frigate. It doesn’t carry any bombers.
Cruisers
-Cruisers have special MAC guns that can partially bypass covenant Shields but punching through them.
Halcyon-Class Cruiser: It is very well armored but it is slower and other than its large MAC gun it's relatively weak for its size/cost; only about the same as a Destroyer. It's strength though is in a big boost through in planet capture.
Marathon-Class Cruiser: The real HC for the humans. It has heavy armor, a cruiser MAC gun, and many missiles. A price is that it isn’t very good at plant capture.
UNSC Carrier: What it name implies, a carrier.
Capitals
Halcyon-Class Cruiser [Refit]: A refitted version of the old cruiser it retains the high armor of its older cousin but gets more missile pods, greater speed, and a triple fire MAC gun [Special ability] but it also is the only ship with access to the researchable ability the Spartan Project [Send a Spartan to a planet and take a chunk out of its health]. Very expensive.
Colony Ship: The colony ship would be pretty well armed but not enough to be a full time combatant it would be a support capital with the ability to colonize worlds. [Maybe the only way I'm not sure]
UNSC Super Carrier: Not very powerful close up, but carries many squadrons of longswords.
Planet Capture
There will be two ways to destroy a planet. The first is the fly down troops onto the surface [kinda like bombard in SoaSE]. Humans get a boost here because all their ships can do this. The second way to attack a planet is to glass it. While humans can do this the covenant will have huge boosts here. Glassing a planet is very powerful but you cannot use the planet for a long period of time. This along with the static defenses and more powerful Covenant ships make the humans powerful on and near their own planets but the covenant rule direct space combat.
Planets defenses for the humans will be Super MAC cannons similar to the gauss cannons in SoaSE but more powerful and greater range. They also gain the boost that their slugs pass right through Covenant shields. They are expensive though.
Covenant
I will write them up later but their ships will be larger, and more powerful in space combat and with shields, but also more expensive to produce and not as good at capturing planets.
I would love to make this mod but I have never modded a game before and I have no graphical talent. Some of the ships also would need to have whole models made from scratch because we don't know what they look like. The Prowler, Destroyer and Carriers come to mind.