Why Do Tanks Split Up in World of Tanks Rather than Mass Forces?

The_Chieftain: The maths in favor of concentrating your maneuver is incontrovertible. 
 There is, however, a major misconception (repeated above) that in order to mass firepower, one must also mass forces. Massing forces does, indeed, result in, for example, being a lovely target for artillery, but there is no need for everyone to be in the same place to shoot at the same target. You just need line of sight, (This was something which it took the US civil war to drive into actual military theoreticians) Obviously, if a team chooses to concentrate its efforts on one area, it runs the risk of being the inferior force in another. They key to success is the “strong” part of the team understanding its force superiority and being aggressive, and the “weaker” parts of the map understanding that they are weaker and playing cautiously. This should not (emphasis on “should”) require that there be a team commander, just a mutual understanding of the situation. If the individual team players, for example, do not realise that they outnumber that Jpz E100 by 5:1 and that -someone- is going to take a hit from it while they swarm it which will be well worth the damage (especially on corridor maps), which should not need someone telling them, then the team as a whole is going to lose because the individual players could not figure out on their own the nature of the battlefield situation.