Allow me to list my own suggestions for troop names. I know a lot about the MEverse, so I'm more familiar with the various military units each of the races have. Humans have distinct units, as well, so don't forget them! Check the wiki for information on the canon units.
TroopName: Frontier Division. These are the standard Alliance Marine units. Yes, this name is canon.
TroopNameArmored: Mako Brigade Combat Team. We all know and love the Mako. It's an IFV, though, not a proper Main Battle Tank, but we don't know of any MBTs in the Alliance, so they will have to do. Even so, they pack some impressive firepower, and the Alliance is a highly mobile fighting force, so it fits anyway.
TroopNamePlanetaryDefense: Garrison Unit. Can't think of anything better. They're just that, garrisoned units. Remember the 212 from Mass Effect 1? Think that.
TroopNameSpecialForces: N7 Special Operations Group. This is a no-brainer. Could shorten the name to N7 Spec Ops Group or N7 SOG.
TroopName: Assault Legion. The turians are very reminiscent of the Roman Empire. I think their infantry units would be organized as legions rather than squads. Divisions work, too. Execution Squads, or "Hastatim", as they're officially called, are not regular infantry. They're more like, well, death squads.
TroopNameArmored: C77 Tyrus Combat Unit. The C77 Tyrus is a turian APC. It's canon, too, it's mentioned in a Cerberus Daily News post from July 2010. (See "Video of IED Explosion on Taetrus Garners Millions of Hits") An alternate vehicle to use is the Jiris IFV. (See "Ground Campaign Underway on Taetrus", June 2010)
TroopNamePlanetaryDefense: Reserve Unit. Pretty much the same as what Solarius said.
TroopNameSpecialForces: Blackwatch Company. Turian Cabals are no joke, of course, but an alternative unit to use is Blackwatch. These guys are the finest soldiers in the turian military, and that's saying something, considering how militaristic the turians are. They're handpicked from units all across the Hierarchy, and are sent on clandestine operations where the safety of Palaven is at risk.
TroopName: Krogan Warband. I think this name fits the krogan infantry unit better. It fits with the way their society works, being broken up into clans and such.
TroopNameArmored: Tomkah Battalion. The Tomkah is a krogan IFV, very similar to the Mako. Come to think of it, there seems to be a total lack of actual tanks in Mass Effect.
TroopNamePlanetaryDefense: Local Militia. Probably the guys guarding the camps and such. Can't think of anything better.
TroopNameSpecialForces: Battlemaster Company. Battlemasters are the most badass krogan out there. They're well-armed, tough as nails and worst of all, they're biotic. They equal ten normal troops in terms of sheer strength. Wrex is a battlemaster, and that should tell you just how deadly they are.
TroopName: Migrant Fleet Marines. The Quarian Marines are the Flotilla's main line of defense on the ground.
TroopNameArmored: Heavy Support Group. What Solarius said, the Quarians can't support heavy armor, let alone produce it.
TroopNamePlanetaryDefense: Migrant Fleet Militia. Well, the quarians don't really have much going for them after the marines, so don't count on these guys. :P
TroopNameSpecialForces: Infiltrator Unit. Closest I can get to an actual Quarian special forces unit in canon. (It's from ME3 multiplayer.)
TroopName: Heavy Infantry Division. Can't argue with that, the elcor are walking tanks.
TroopNameArmored: Siege Unit. The elcor are already walking tanks, you can't go much farther than that.
TroopNamePlanetaryDefense: Heavy Militia. What Solarius said.
TroopNameSpecialForces: Special Weapons Unit. Since the elcor regularly make use of heavy weapons, one could imagine them sticking particularly powerful and experimental gear on whatever special ops units they have, if they even exist. I'd say that these elcor are particularly adept at wreaking havoc behind enemy lines, leaving a trail of destruction in their wake before the enemy can even react to them. This isn't canon, of course, but hey, it's a fun thought.
Well, that's all I've got. What do you think?
< Message edited by Son_of_Orion -- 6/3/2013 11:14:42 PM >