This debate is between IrishHitman and timberrattler.

Combatants:
Irish Raiders vs. American Highwaymen

Time:
One year after first infection in homo sapiens.

Location: Area around Woodbury, Tennessee, the United States of America.

Group Descriptions:
Irish Raiders:
A group of predominantly Irish people, who have crossed the Atlantic Ocean seeking better hunting and trading grounds.
The group is structured into three subgroups, two combat units and a support unit. Personnel are rotated between these three subgroups regularly for cross training.
The two combat units are broken up into squads, which vary in size according to the combat situation encountered. Decisionmaking comes from the group as a whole, via direct democracy. Leadership is provided by a commander who forfeits their right to vote to gain the right to command the group in battle and veto proposals.

American highwaymen:
A group of Americans who live in the area in which the raiders are travelling.
They are small in number. They live locally, off the land and by seizing supplies from passing people.
The group has four combatants who are highly proficient with firearms that they have used for years.

Combat Relevent Information:

Irish Raiders:
Standard Personal Weapons: Various, Steyr AUG prevalent
Side Arm: Various, H&K USP prevalent
Squad Support Weapons: FN MAG 7.62mm General Purpose Machine Gun
AT/AF Rocket Launchers/Rifles: None
Medium Support Weapons: Browning M2 12.7mm HMG
Artillery: None
Vehicles: F350s, Land Rovers, Nissan Patrols, Panhard AML armoured cars, minibuses, all modified.
Total Personnel: Approx: 60-80 full time combatants.

American Highwaymen:
Standard Personal Weapon: Various, Chinese SKS 7.62 x .39mm prevalent
Side Arm: Various, 1911 .45 Springfield, military-spec prevalent
Squad Support Weapons: None
AT/AF Rocket Launchers/Rifles: Remington .308, bull barrel, Leupold sights.
Medium Support Weapons: Remington 870 12 gauge, pump action, 28" barrel, modified choke. 00 buck munitions.
Artillery: None
Vehicles: Tennesse Walking Horse geldings. Trained to tolerate gunfire.
Total Personnel: 4

Combat Positives:
Irish Raiders:
Combat Capability: The raiders have a superior arsenal to call upon and a numerical superiority.
Range: Having motor vehicles and a greater range to live off, the raiders can go further.
Infected threat minimal: The infected do not pose a significant threat to the raiders provided they stay clear of areas of high population density and wandering swarms from those areas.
Intelligence: The raiders have a better picture on the regional, national and international situation than most groups.
Operational Flexibility: Due to the combination of the above, the raiders are highly flexible in how they operate.

American Highwaymen:
Local Knowledge: The highwaymen have extensive local knowledge, which allows them to move more effectively in the battlespace among other things.
Preparation of battlespace: The highwaymen are able to prepare traps and plans well in advance of actual combat.
Terrain transport: Due to the good trail horses available to the raiders, they are capable of entering forests and mountainous areas better than the raiders.
Born-to-Kill: Unlike the raiders, the American highwaymen have been handling weapons since their early years, and are generally better shooters.
Local Support: Other survivors in the area will know the highwaymen well, and will be immune from assaults by them.

Combat Negatives:
Irish Raiders:
In unknown territory: Although the raiders have maps, they do not possess intimate knowledge of the area they are operating in.
Large numbers: The raiders cannot stay in the area for extended perioids without trading or raiding, due to the large numbers of people in the group.

American Highwaymen:
Range: The highwaymen cannot stray far from their base of operations.
Combat Capability: The highwaymen cannot enter a conventional firefight due to the numerical advantage of arms and personnel of the raiders

Conclusion:
The raiders are capable of utterly defeating the highwaymen, but only if they present a target for the raiders to attack.
The highwaymen are capable of defeating a section of the raiders' group, carrying off their supplies via the horses and getting away with it, but must be careful regarding their range, as the raiders could easily search the surrounding area to find them.

The outcome depends on how the highwaymen attack, how the raiders react, and the subsequent decisions of the raiders.
Both sides have made their own hypothesis on how each side would react HERE.

Scenario:
The raiders proceed south on Tennessee Route 53, heading towards Lynchburg, Tennessee, which has a sizable survivor group.
They plan to raid the Jack Daniel's facility, which information suggests is still in limited operation.
Their convoy is a staggered line, with the armoured cars in the front, protecting the supply and support vehicles, while the lightly armoured trucks take up the centre and rear.
There is also a truck that travels a mile ahead of the convoy to scout.

The highwaymen are waiting north of Woodbury, TN, for a target. They are positioned in the middle of two bends in the road, to give them an advantage to ambush vehicles with the advantage of line of sight. They have a cart hidden in the trees to shove onto the road, and three shooters positioned on the opposite side. The fourth shooter starts the cart onto the road and spots targets.

The raider's scout is not attacked as it passes the highwaymen's ambush point, as the spotter has heard more cars in the distance, and is suspicious about the armour on the scout car. Three minutes later, his suspicions are justified as the armoured section of the convoy comes into view. The spotter signals to prepare to attack, as the rest of the convoy also enters his line of sight.

The armoured cars, pickups and supply trucks drive by, which the highwaymen ignore.
Eventually, after several minutes, the end of the convoy begins its turn into the first corner.
The last truck is losing ground due to being on the outside of the corner, it's four occupants seeming entirely unaware of what is about to happen.

The highwaymen strike. The spotter removes the chucks from the wheels of the cart, and it speeds down the brief slope just in time for the last truck to slam into it.
The shooters on the opposite side of the road, shoot into it, killing the driver and the rear passenger. The convoy keeps driving, as it cannot turn around without creating a jam.
The surviving raiders disembark behind their vehicle, and prepare their assault rifles as bullets continue to fly in their direction.

The spotter shoots them with a shotgun from behind.
The highwaymen begin searching the vehicle quickly before the convoy reach a place where they can turn.
They finish packing their bags with the weapons, ammunition and supplies that were in the truck when the scout car returns.

The highwaymen flee through the forest under small arms fire from the scout, and dump the captured guns for speed. They make it back to their horses, and hike it cross country west for a while. The raider convoy continues to Woodbury, which is abandoned with the exception of a dozen or so infected. The raiders put out spotters in the outskirts of the town, and spot the highwaymen a few miles away as they escape on horseback west along TN Route 1. This information is not relayed quickly enough, and a vital moment for the raiders is lost.

The raiders stage a vote on whether to track down the highwaymen or continue, and the result comes up as a majority in favour of tracking them down, mostly out of anger and the possibility of a well supplied group to raid. The convoy waits until night.

The highwaymen make it back to their base of operations, and settle down a bit, but are still shaky due to the size of the group they have just successfully attacked.

Night falls.
The convoy moves west in the same direction as the highwaymen went.
Spotters dispatched to a hill with a commanding view reported a strange amount of infected around a house in a small valley ahead just before sunset.
As the convoy moves to investigate, the spotters report gunfire. The highwaymen are found.

The raiders split up, with a group moving to the forest east of the highwaymen base, and the rest parking up beside a cemetary.
Using a pair of NV goggles, the raiders inspect the base. It's a large house with stables, surrounded by wooden and metal defences to keep out the infected.
The leader wishes to break off the attack, as the house looks too small to yield anything of value, but the group do not want to.

A decision is made.
Several flares are sent up to illuminate the area around the house, and the armoured cars move up the road to distract the highwaymen inside while the infantry attack via the forest.
The highwaymen cease firing on the infected, who turn their attention to the convoy, but are cut down easily. The infantry reaches the wooden defences, just as the highwaymen begin to shoot at them. The raiders set the defences on fire with petroleum, and lob petrol bombs at the house within as well.

As the fire begins to grow, the raiders shoot their weapons into the house from the trucks, to allow the foot troops to retreat, killing one highwayman and injuring another.
The convoy proceeds back down the road, only to be attacked by other survivors on the same road who did not previously show themselves.
Machinegun fire suppresses them as the raiders move, and escape back to Woodbury.

The highwaymen, no longer threatened by the infected, extinguish the fires in the house, but struggle to do the same with their outer defences.
The blaze continues into the morning, eventually burning itself out. The defences are destroyed on two sides, but can be repaired.

The raiders continue south down TN Route 53, after recovering the vehicle that was attacked and burying their dead.