MArathon was a greek battle. It was during the persian wars in 490 BC. To this day it is studied by modern militaries. This is the first time the flank has been historically recorded in combat. To this day it has been refined, but some stuff can just mess the normally winning strategy fail.
The first thing that could mess this up is co-ordination. Of course, like at marathon, the best way is to fake a retreat, drawing the enemy in behin you. Your troops would the simultaneously emerge from hiding and shoot the enemy from the sides and partially in the back. If one of the flanks shoots as much as 10 seconds behind, well trained enemies could turn on the flank that has fallen behind, and cause sufficient casualties to escape. Not very likely, but it all depends on how trained your troops and the opponents troops are.
second is firepower. Obviously, flanking is best done with hi-cap full autos. If your team is using semi automatics, low caps, springers, even mid-caps, the enemy could be given time to retaliate and thus cause casualties, for potential escapes. '
third is numbers. The flank is best done with equal or greater numbers. Insufficient numbers means that well trained enemies could take aim by using say, two of their shooters, on one of yours.
Fourth is perfect surprise. If the element of surprise is compromised, then an enemy could give you casualties, even before you open fire. Make sure the flankers are well concealed until the opportune time to attack has arrived.
To perfectly master a greek flanking requires strict commandeering and repetitive training.
Units: You need a good ratio of units. 4 Riflemen:3 Machine Gunners:1 Sniper:5 enemies. While rifleman make the bulk of the force, you need maintained suppressing fire from machine guns to strafe the targets if the enemy may run. The sniper should be used to announce when the attack begins, as soon as the sniper fires, the rounds should start firing. If necessary, the riflemen can advance and take out enemies who have somehow managed t get in a position that has saved them from the fire. riflemen will also make sure the enemy is in fact dead.
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