So, was thinking about it and I have a few ideas...
First off, as most people are aware, Sins has two sub-factions per race in its vanilla state. An interesting idea (Although perhaps stretching the canon a little) Would be to have sub-factions led by specific UNSC hero's from within the lore. Ones that would make sense though. Such as:
- Fleet Admiral Terrance Hood: Commander of the UNSC Home fleet. As a sub faction, Hood would gain special defensive bonuses specific to his faction. Such as slightly increased armor, damage and range on SMAC platforms, cheaper and more effective bombardment defenses, and a series of bonuses to ships fighting inside of friendly gravity wells. Perhaps even the unique ability to mount AAA Helix cannons onto his SMAC platforms, affording them some defense against the inevitable strike craft waves (obviously these would be balanced and not quite as strong as AAA Helix cannons on say... An Anchor station.)
Hoods faction would not be too dissimilar to the TEC loyalists in the sense that he focuses on defenses. Possibly allowing for better coordination and efficiency relating to home defenses. He would be as capable militarily as any other commander, however he would be better effective at turtle-ing up. Planets under his control could also gain bonus health and population as well as increased tactical slots to represent his defensive nature.
- Carl "Buster" Patterson (See: http://halo.wikia.co.../Carl_Patterson ): I initially wanted to suggest Admiral Cole for this role as I am trying to stick with some more well known admirals, but on thinking about it Patterson fits a little better. Patterson would essentially fill the role of the TEC rebellion. Believing in full on frontal assaults and taking the fight to the covenant. With that in mind he would have access to research and bonuses geared towards the offensive side of the conflict.
Such as increased thruster speeds allowing his ships to close the gaps faster, shorter reload times for all weapons (including shiva warheads) increased damage for all weapons. The downside to this steamroller movement of his is that he doesn't take particularly good care of the colonies he owns (They're not in disrepair or anything but they're not as well defended like say... Earth or Reach) With that in mind his planets might suffer from reduced population and a higher under-development loss rate, or reduced tactical slots. However he would have an increase in ship production also. As well as perhaps, a change to his starbase rules, making them follow rules similar to the Vanilla Sins Super weapons. Allowing him to place down one for every 3 planets he owns (in vanilla it is every 4 planets and if you're the TEC loyalists with Novalith Deregulation it is every 2 planets you own)
This would not necessarily break his defensive abilities, but it would highlight his offensive capabilities, as well as making it so that choosing him may constitute you steam rolling things, but you have to be tactical about how you place down defenses in case the steam roller hits a wall. Scouts would likely also have slower movement or less use in his faction as according to his lore, he chose to blunder in head first, instead of scouting first. I also imagine that to represent hastily set up colonies, a feature along the lines of a "Slow start" could be implemented, where for say... 5 minutes following the immediate colonization of a planet, resource extraction from that planet is halved, picking up again when the 5 minutes is over.
- ONI Liaison Dr. Halsey/Cortana: The ONI Faction would have the experimental technologies, naturally. Such as specialized scouting vessels (ONI Prowler instead of sloop) which would have abilities other scouts did not such as timed explosives, remote sensors (Things of this nature, using vanilla skills as place holders). Or possibly even active camouflage. The larger ships would be fit with energy shielding, at the cost of increased mass, reduced hull and armor, and perhaps reduced speed and turn rate, so as to represent the loss of power produced by the shield generators. All strike craft would be replaced by Sabres regardless of the ship they were mounted on. Oni would also have access to specialized infiltration teams.
I noticed that in SOTP, the planetary bombardment (for the UNSC at least) isn't so much a bombardment as an invasion, the ships fire drop pods (And have abilities to bolster troop numbers on the ground aka "Boots on the ground". If this is the case, and feel free to correct me if I am wrong. Then ONI would have access to some special abilities that aided in colonization, increased the speed of research, decreased the costs of research (Perhaps).
I think ONI would also have access to some specialized AI upgrades that the other UNSC factions do not gain. Such as installing a second AI into a ship. The effects of which would change based on the ship. For example, on a Thermopylae Super Carrier, one AI would focus on running the ship as normal (Movement, shielding, weapons etc.) the Second AI could then focus purely on improving the efficiency of the ships Strike Crafts, allowing them access to things such as the "Evasive maneuvers" ability, with which they would have a chance to dodge incoming fire or perform maneuvers that allowed them to get into more favorable firing positions (Similar to what F22 Raptor pilots can do when they use the vectored thrust to make insane turns and such.)
ONI would also have access to prototype designs, Perhaps a prototype ship fielding a new MAC design. The gun is powerful enough to obliterate every non capital covenant ship and several of the more basic capital ships even while it is shielded. However, firing the cannon would cause the systems on board the ship that require energy to shut down for 15 seconds after firing (Sub-light engines disabled, Shields removed 100%, Shield recharge disabled, MAC cannons disabled, Abilities Disabled) This would mean the ship is vulnerable after firing a shot, but it can still fight back with archer pods and helix cannons while it recharges. The ship could possibly come back online in stages. Such as:
Zero moment (instant of firing experimental MAC round)
- Abilities disabled: 15 seconds
- MACs Disabled (The regular sized MAC guns all UNSC ships are fitted with): 15 seconds
- Shields removed:100% Shield recharge disabled: 10 seconds
- Sub-light thrusters Disabled: 5 seconds
This would mean that the ship comes online in several stages, which would be really cool. After 5 seconds, power is routed back into the engines, allowing it to move about again, after 10 seconds it will start recharging all shields again, now it can move and has better shielding, and then at 15 seconds it will be able to use abilities and fire the regular MAC guns again. The time value of 15 seconds is a place holder, it could be changed, although to be longer would be more balanced.
Final idea isn't exactly faction related, but ties into the ONI super ship I mentioned above. In that, a ship of a similar concept, would be an awesome titan class ship for the UNSC. The SMAC gun built into it that drains all of the ships power, would be an ability, with a much greater range than that of the regular MAC guns. Think... Snipe, from the TEC rebellion titan, only a little more costly to use.
That concludes my faction ideas for the UNSC. Sorry for text wall. Will add something for the covenant when I figure out exactly how I would like to do this sort of thing for them.