In Team Yankee
As far as Observation teams go, the M113 is rather well-suited to the role. Having some relatively tough armour and no big fancy gun to tempt you into giving up your Gone to Ground, it can be surprisingly resilient under sustained fire. That being said, it's title of OP is rather misleading, as it is most certainly not overpowered.
Yes... It's the FIST... You may make all the Fisting jokes you like...
Now for the rulings: purchased as an add-on with M109 and M106 batteries for one point, you get a very useful unit that ranges in artillery with a +1 bonus for their assigned unit and an additional unit leader that can call for fire.
Players taking artillery will find these absolutely essential. While utility smokes don't need all their shots to land, you can conserve more smoke shots and expect less to fail. With killing artillery, however, this unit is absolutely essential. As any Soviet player knows, ranging in on the first time ensures that you get the most damage out of your big guns. With US M109s taking special warheads, the OP is an auto-include for making sure those cluster mines or 155mm HE shells hit your enemy on time, and on target.
Nearly the same as the US' variant, but much more valuable thanks to a stronger skill value. The gun has a higher moving ROF for lower firepower and AT, but why would you be using an OP to lay down fire anyway?
The Germans lose scout which means that they don't get an additional +1 cover bonus when gone to ground: something which you might find rather worrying. You also have a down-grade to infrared, making you much more vulnerable to smoke. Fortunately, you will be calling for fire and passing on a 2+: enough to make up for these failings.
Sneaky Canuck box. Like the German variant, it too has a 3+ skill value and consequently will be more reliable when ranging in.
A scouty scout. Let's see... The .50 is gone, replaced by a 7.62 MG, which can do AA... It's basically pointless in that role, but you can try. You lose 4"/10cm of range on that MG of yours, in exchange for FP 6 and +1 ROF on the move. Lovely. They again get a downgrade to IR instead of Thermal Imaging, but make up for it with better Skill, Counterattack, Morale, Remount, Courage, by 1.
The M113 OP isn't a specialized vehicle so much as a doctrinal specialty. While M113's are useful for ferrying soldiers to the frontlines, they're also useful for sneaking a single, smaller team out ahead of the army to spot targets for artillery, since most artillery pieces have ranges beyond line-of-sight and may want to fire from behind cover. Ideally, the M113 would be concealed while its team disembarks to a nearby position to watch from. With the unused passenger space, an observer team will typically bring extra radios and replacement parts. The team's radio operator may stay inside the M113 if coordinating between multiple batteries.
|Israeli Forces in Team Yankee|
|Tanks:||Merkava - M60 Patton|
|Transports:||M113 Armored Personnel Carrier|
|Troops:||IDF Infantry Platoon|
|Artillery:||M109 Howitzer -M106 Heavy Mortar Carrier -M125 Mortar Carrier|
|Anti-Aircraft:||M163 VADS - ZSU 23-4 Shilka - M48 Chaparral - Redeye SAM Platoon|
|Tank Hunters:||Pereh - M150 TOW - Jeep TOW|
|Recon:||M113 Recce - Jeep Recce|
|Aircraft:||AH-1 Cobra Attack Helicopter - A4 Skyhawk|
|US Forces in Team Yankee|
|Tanks:||M1 Abrams - M60 Patton - M551 Sheridan - RDF/LT|
|Transports:||M113 Armored Personnel Carrier - UH-1 Huey - AAVP7 - Bradley Fighting Vehicle|
|Troops:||US Mech Platoon - Marine Rifle Platoon - Huey Rifle Platoon - HMMWV Machine Gun Platoon - Light Motor Infantry Platoon|
|Artillery:||M106 Heavy Mortar Carrier - M109 Howitzer - LAV-M - M270 MLRS|
|Anti-Aircraft:||M163 VADS - M48 Chaparral - M247 Sergeant York - HMMWV SAM|
|Tank Hunters:||M901 ITV - HMMWV-TOW - LAV-AT|
|Recon:||M113 FIST- M113 Scout Section - HMMWV Scout Section - LAV-25 - Bradley Fighting Vehicle|
|Aircraft:||A-10 Warthog - AV-8 Harrier - AH-1 Cobra Attack Helicopter - AH-64 Apache Attack Helicopter|
|West German Forces in Team Yankee|
|Tanks:||Leopard 2 - Leopard 1|
|Transports:||Fuchs Transportpanzer - Marder II Zug - Marder Zug - M113 Armored Personnel Carrier|
|Troops:||M113 / Marder Panzergrenadier Zug - Aufklärungs Zug - Fallschirmjager Zug - Gebirgsjager Zug - Jager Zug|
|Artillery:||Raketenwerfer Batterie - M109 Howitzer - M113 Panzermörser Zug - M270 MLRS|
|Anti-Aircraft:||Roland Flak Batterie - Gepard Flakpanzer Batterie - Fliegerfaust Gruppe - Wiesel Flugabwehr Zug|
|Tank Hunters:||Jaguar Jagdpanzer - Kanonenjagdpanzer - Wiesel TOW|
|Recon:||Luchs Spah Trupp - M113 OP - Marder II Zug|
|Aircraft:||Tornado - BO-105P|
|Canadian Forces in Team Yankee|
|Infantry:||Canadian Mechanized Platoon|
|Artillery:||M109 Field Battery - M125 81mm|
|Anti-Aircraft:||ADATS - M113 Blowpipe|
|Tank Hunters:||M150 TOW|
|Recon:||Lynx RECCE Patrol - M113 OP|
|US Support:||M1 Abrams - M60 Patton - US Mech Platoon - A-10 Warthog|
|WG Support:||Leopard 2 - Marder Panzergrenadiers - BO-105P - Tornado|